Abaloparatide formulations and methods of testing, storing, modifying, and using same

ABSTRACT

Provided herein are newly discovered methods of analyzing abaloparatide samples for abaloparatide isomers. Additionally, methods of storing and treating with abaloparatide in view of the newly discovered abaloparatide isomers are described.

PRIORITY CLAIM

This application is a continuation of U.S. application Ser. No.15/967,504, filed Apr. 30, 2018, which claims the benefit of U.S.Provisional Application No. 62/492,022, filed Apr. 28, 2017, thecontents of which are incorporated herein by reference in its entirety,including drawings.

BACKGROUND

Conventionally, osteoporosis is treated by administration ofantiresorptive agents to suppress bone resorption. The most common ofthese treatments is oral or intravenous administration ofbisphosphonates. However, an undesirable side effect of bisphosphonateadministration is reduced bone formation (MacLean 2008). This has led tothe evaluation of anabolic agents as an alternative to antiresorptives.

Parathyroid hormone (PTH) is an anabolic agent that enhancesosteoblastic bone formation. Teriparatide (Forteo®), a recombinant formof the N-terminal 34 residues of PTH (PTH-1-34), is currently the onlyanabolic agent approved for treatment of osteoporosis. Teriparatide actsby a mechanism that involves stimulating new bone formation (along withresorption) and reconstituting internal bone microarchitecture (Recker2009; Dempster 2012; Ma 2011). Another anabolic agent, abaloparatide, iscurrently in late-stage clinical trials for treatment of osteoporosis.Abaloparatide is an analog of a secretory form of parathyroidhormone-related protein (PTHrP; UniProt Accession No. P12272). PTHrP andits other secretory forms (e.g., PTHrP(1-36), PTHrP(38-94), andosteostatin) and analogs thereof have also been investigated aspotential treatments for osteoporosis in recent years. PTHrP and PTHshare homology at their N-terminal ends, and both bind to the sameG-protein coupled receptor, PTH receptor type-I (PTHIR). Despite thiscommon receptor, PTH primarily acts as an endocrine regulator of calciumhomeostasis, whereas PTHrP plays a fundamental paracrine role in themediation of endochondral bone development (Kronenberg 2006). Thedifferential effects of these proteins may be related not only todifferential tissue expression, but also to distinct receptor bindingproperties (Pioszak 2009; Okazaki 2008; Dean 2008).

SUMMARY

As disclosed herein, improvements to the analytical procedures forevaluating abaloparatide formulation, including active pharmaceuticalingredient (API) and formulated drug product, have been developed. Theseimproved procedures have resulted in the identification of previouslyunknown abaloparatide-derived or -related degradants and/or impurities(hereinafter collectively referred to as “related peptides” or“abaloparatide related peptides”): beta-Asp10, cyclo-Asp10, cyclo-Asp17,abaloparatide truncated peptide (3-34) (“ATP(3-34)”), and abaloparatidetruncated peptide (4-34) (“ATP(4-34)”). The experimental resultsprovided herein describe the identification, peak isolation, andcharacterization of these abaloparatide related peptides. Based on thesefindings, there is a need for methods of detecting the presence and/ormeasuring the actual or relative amount of these abaloparatide relatedpeptides in abaloparatide formulations, formulating and storingabaloparatide in a manner that monitors and/or controls for theserelated peptides, and administering abaloparatide formulations in amanner that takes into account the actual or predicted presence and/orthe actual or relative amount of the related peptides (as well asabaloparatide itself). The present disclosure provides each of thesemethods, as well as abaloparatide formulations comprising abaloparatideplus one or more of the related peptides, and the use of theseformulations in the treatment of various conditions including, forexample, osteoporosis, e.g., post-menopausal osteoporosis,glucocorticoid-induced osteoporosis, or male osteoporosis,osteoarthritis, or bone fracture healing.

Provided herein in certain embodiments are methods of detecting andquantifying the presence of one or more of abaloparatide, beta-Asp10,cyclo-Asp10, cyclo-Asp17, ATP(3-34), and ATP(4-34) in an abaloparatideformulation, including abaloparatide API or formulated abaloparatidedrug product. In certain embodiments, these methods further comprisemeasuring the actual or relative amount (i.e., the amount as apercentage of total abaloparatide) of these peptides in an abaloparatideformulation at a given time. In certain embodiments the abaloparatideformulation is an aqueous abaloparatide formulation, anddetection/measurement takes place immediately after the formulation isconstituted, i.e., after API is constituted into an aqueous formulationsuitable for drug delivery (t=0 of the formulated drug). In otherembodiments, detection/measurement takes place after the aqueousabaloparatide formulation has been stored for one or more definedperiods of time at one or more defined temperatures. In certainembodiments, the detection and measurement methods provided herein maybe used to evaluate the degradation of an abaloparatide formulationand/or the levels of impurities, to determine or predict its totalstorage life or remaining storage life, or to evaluate storageconditions, methods, or timeframe conducive to use. In certainembodiments, the detection and measurement methods may also be used todetermine the suitability of an abaloparatide formulation foradministration to a subject or a patient population, to predict thetherapeutic efficacy of an abaloparatide formulation, or to calculatethe appropriate dosage of an abaloparatide formulation. In certainembodiments, the detection and measurement methods and the compositionsprovided herein may be incorporated into a method of treating anabaloparatide-addressable condition in a subject in need thereof, forexample a method of treating osteoporosis, e.g., postmenopausalosteoporosis, glucocorticoid-induced osteoporosis, or male osteoporosis,osteoarthritis, or bone fractures.

Provided herein in certain embodiments are methods of analyzing anaqueous formulated abaloparatide drug product, including quantitatingthe presence of one or more of beta-Asp10, cyclo-Asp10, cyclo-Asp17,ATP(3-34), and ATP(4-34). In certain embodiments, these methods are usedto evaluate storage conditions, and to determine whether the formulationis suitable for therapeutic administration, for example by determiningwhether the actual or relative amount of the peptideimpurities/degradants are at or below a predetermined threshold value.In certain embodiments, the methods of analyzing and storingabaloparatide provided herein may be incorporated into a method oftreating a condition in a subject in need thereof, for example a methodof treating osteoporosis, e.g., postmenopausal osteoporosis,glucocorticoid-induced osteoporosis, or male osteoporosis,osteoarthritis, or bone fractures.

Provided herein in certain embodiments are methods of storing anabaloparatide formulation, including abaloparatide API and formulatedabaloparatide drug product, in a manner that limits the amount ofabaloparatide related peptides to at or below a predetermined thresholdlevel (for a given time and/or conditions), as well as the therapeuticuse of formulations stored according to these methods. In certainembodiments, these methods comprise storing the abaloparatideformulation for a specific period of time and/or at specifictemperature. In certain embodiments, these methods comprise storingabaloparatide API and releasing API for further processing. In certainembodiments, the storage methods provided herein may be incorporatedinto a method of treating a condition in a subject in need thereof, forexample a method of treating osteoporosis, e.g., postmenopausalosteoporosis, glucocorticoid-induced osteoporosis, or male osteoporosis,treating osteoarthritis, and/or accelerating the rate or improving theoutcome of bone fracture healing. For example, in certain embodiments,the formulation may be administered to a subject for the first time atthe end of the first period storage period, and in certain embodimentsthe formulation may be administered for a second time and any subsequenttimes over the course of the second storage period. In certain of theseembodiments, the formulation is stored in a multi-injection pen, whereinthe pen is used to inject a first dosage at the end of the first periodand the beginning of the second period, and then to inject subsequentdosages over the course of the second period according to a particulardosage and/or schedule. In certain embodiments, an abaloparatideformulation stored in accordance with the methods provided herein may besubject to one or more of the methods of analyzing for beta-Asp10,cyclo-Asp10, cyclo-Asp17, ATP(3-34) and ATP(4-34) in an abaloparatidecontaining sample provided herein at one or more points over the courseof the storage period. For example, the formulation may be subjected toa method of detecting and/or measuring the actual or relative amount ofbeta-Asp10, cyclo-Asp10, cyclo-Asp17, ATP(3-34) and ATP(4-34) in orderto assess stability and/or suitability for administration. These methodsmay be performed at one or more predetermined intervals, at randomlyselected intervals, or immediately prior to the first and/or anysubsequent administrations. In certain of these embodiments, the storedformulation is only administered if the actual or relative amount ofbeta-Asp10, cyclo-Asp10, cyclo-Asp17, ATP(3-34) and ATP(4-34) is at orbelow a predetermined threshold value.

In certain embodiments, the detection, measurement, removal, andpurification methods provided herein comprise subjecting anabaloparatide formulation, e.g., a sample or lot, to high performanceliquid chromatography (HPLC) and/or ultra-high performance liquidchromatography (UPLC). In certain embodiments, the UPLC utilizes acolumn containing average mean particle diameters of less than 3.0microns, or less than 2.5 microns, or less than 2.0 microns.

In certain embodiments, the HPLC and/or UPLC systems used in the methodsprovided herein utilize a buffer, for example a phosphate buffer, in themobile phase. In certain of these embodiments, the phosphate buffer maybe supplied as its ammonium phosphate salt. Phosphate salts withdiffering cationic counterions may be used (e.g., Na+, K+, and othersknown to those of ordinary skill in the art). In certain embodiments, adifferent ionic buffer (e.g., sulfonate) can be added to the HPLC/UPLCeluent to increase resolution between peaks, for example, the peaks fromabaloparatide, beta-Asp10, cyclo-Asp10, cyclo-Asp17, ATP(3-34), andATP(4-34). In certain embodiments, the buffer is used to establishand/or maintain the pH of the mobile phase. In certain embodiments, thepH of the buffer used in a binary eluent is about pH 6 to 10, 7 to 9,7.5 to 8.5, or 7.6 to 8.0, for example about 7.8. In certainembodiments, the buffering agent is soluble in water at sufficientconcentrations to retain the pH at the desired range in the aqueoussolvent prior to mixing with another solvent. In other embodiments, theamount of buffering agent is sufficient to maintain the HPLC/UPLCsolution phase (water plus any other solvent or combination of solvents)within the desired pH range, though generally it is more reliable tomeasure pH in the aqueous phase before mixing with a non-aqueousco-solvent. In certain embodiments, the desired pH range is establishedwith a mono-basic phosphate buffer, for example NaH2PO4, NH4H2PO4, orthe like. In certain embodiments, a sulfonate buffer can be used toreach and buffer the desired pH range.

In certain embodiments, the HPLC and/or UPLC systems used in the methodsprovided herein utilize a predominately binary solvent system, and incertain of these embodiments the two solvents togethercomprise >90%, >95%, >98%, or >99% v/v of the mobile phase. In certainembodiments, one part of the mobile phase is aqueous and one part of themobile phase is acetonitrile or methanol and in certain embodiments athird solvent (or combination of solvents) is used at a total of ≤10%v/v of the mobile phase. By way of non-limiting example, a predominatelybinary solvent system could contain 60% water, 30% acetonitrile, and upto 10% another solvent or combination of other solvents, e.g., 10%methanol, 5% methanol and 5% ethanol, or any other combination thatmeets the necessary guidelines. In certain embodiments, the aboveconditions are used in an UPLC system.

Provided herein in certain embodiments are formulations or APIcomprising abaloparatide plus one or more of beta-Asp10, cyclo-Asp10,cyclo-Asp17, ATP(3-34) and ATP(4-34). In other embodiments,abaloparatide API or aqueous formulations have been stored withinspecified periods of time under specific temperature conditions. Incertain embodiments, the formulated drug products are aqueous andcomprise between 1.8 mg/mL and 2.2 mg/mL of abaloparatide, or between1.86 and 2.10 or between 1.90 and 2.10 or about 2.0 mg/mL. In certainembodiments, the formulation are pharmaceutical formulations comprisingone or more pharmaceutically acceptable excipients in addition to theabaloparatide.

In certain embodiments, the abaloparatide API provided herein comprises<0.5% beta-Asp10, <0.5% cyclo-Asp10, <0.5% cyclo-Asp17 and whereATP(3-34) and ATP(4-34) are together <1.0% and wherein said API furthercomprises >97% of abaloparatide of the total peptide content in the API.In some embodiments, the API is stored at -20±2° C.

In some embodiments, an aqueous formulation of abaloparatide comprises<1.0% beta-Asp10, <0.5% cyclo-Asp10, <0.5% cyclo-Asp17, <0.5% ATP(3-34)and <0.5% ATP(4-34) and wherein said aqueous further comprises >97% ofabaloparatide of the total peptide content in the aqueous abaloparatideformulation at t=0 (upon initial formulation of the API into an aqueousformulation).

In certain embodiments, the formulations provided herein are aqueousformulated drug products stored for 0-23 months or 0-35 months, at 2-8 °C., and about 0-1 month at room temperature, e.g., 20-25° C. or about25±2° C., that comprise abaloparatide and beta-Asp10, and in certain ofthese embodiments beta-Asp10 represents ≤5% or between 0% to ≤5%, 0 to4%, 0 to 3%, or 0.1% to 5%, or 0.5% to 4.5%, or 0.5% to 4.0%, or 0.1% to≤5%, 0.5% to ≤5%, or 1.0% to ≤5% % of total peptide content in theformulation. In certain embodiments, the formulations provided hereinare aqueous formulated drug products stored for 0-23 months or 0-35months, at 2-8° C., and for about 0-1 month at room temperature, e.g.,20-25° C. or about 25±2° C. that also comprise cyclo-Asp10 and/orcyclo-Asp17 and/or ATP(3-34) and/or ATP(4-34), and in certain of theseembodiments each of said cyclo-Asp10, cyclo-Asp17, ATP(3-34) andATP(4-34) is present in an amount of ≤0.5% of peptide content in theformulation. In some embodiments, the abaloparatide content is ≥93% ofthe total of the peptide content in the sample. In some embodiments, amethod of establishing suitability of an abaloparatide manufacturingprocess and drug product comprises formulating abaloparatide API into anaqueous vehicle, wherein said abaloparatide API is first analyzed anddetermined to contain ≤0.5% beta-Asp10, ≤0.5% cyclo-Asp10, ≤0.5%cyclo-Asp17 and where ATP(3-34) and ATP(4-34) are together ≤1.0% andwherein said API further comprises ≥97% of abaloparatide of the totalpeptide content in the API and further determining that the initiallyprepared aqueous abaloparatide containing formulation (t=0) comprises≤1.0% beta-Asp10, ≤0.5% cyclo-Asp10, ≤0.5% cyclo-Asp17, ≤0.5% ATP(3-34)and ≤0.5% ATP(4-34) and wherein said aqueous further comprises ≥97% ofabaloparatide of the total peptide content in the aqueous abaloparatideformulation and further embodiments, storing said aqueous abaloparatideformulation for 23 months and then storing at 25±2° C. for 1 month or 35months and then storing at 25±2° C. for 1 month at 2-8° C. and thenstoring at 25±2° C. for 1 month and evaluating the drug product duringand after said storage period and in certain of these embodiments eachof said cyclo-Asp10, cyclo-Asp17, ATP(3-34) and ATP(4-34) is present inan amount of ≤0.5% of peptide content in the formulation and theabaloparatide content is ≥93% of the total of the peptide content in thesample.

In certain embodiments wherein a formulation provided herein is aformulated abaloparatide containing drug product, the formulation has apH between 2-7, 3-6, 4-6, 4.5-5.5, or 4.7-5.5, and in certain of theseembodiments the pH is about 5.1 or about 5.2. In certain embodiments,the formulation comprises a buffer, and in certain of these embodimentsthe buffer is an acetate buffer, for example acetic acid or sodiumacetate, or a phosphate buffer, for example potassium phosphate. Incertain embodiments, the buffer is in a concentration range sufficientto provide the desired level of buffer capacity, for example 0.1 mM to60 mM, 0.5 to 50 mM, 1 to 10 mM, 4 to 8 mM, or about 6 mM.

In certain embodiments wherein a formulation provided herein is aformulated drug product, the formulation comprises an antimicrobialagent, for example a compound with a phenolic group such as chlorocresolor phenol, at a concentration sufficient to provide anti-microbialeffect. In certain embodiments, the antimicrobial agent may be phenol ata concentration of ≤8.0 mg, for example ≤5.0 mg/mL or about 5.0 mg/mL.In certain embodiments, the antimicrobial agent further serves as anantioxidant preservative, increasing the integrity of abaloparatide inthe formulation by reducing the rate of decomposition over theshelf-life of the formulation, for example over 23 months at 2 to 8° C.followed by 1 month at 20-25° C. or about 25±2° C., or over 35 months at2 to 8° C. followed by 1 month at 20-25° C. or about 25±2° C. In certainembodiments, the antimicrobial agent may increase the integrity ofabaloparatide in the formulation over longer time periods or widertemperature ranges. In certain embodiments, the antioxidant effect maybe more measurably demonstrable over increased storage times, elevatedtemperatures, or other formulation variables.

Provided herein in certain embodiments are methods of treating acondition in a subject in need thereof, e.g., a method of treatingosteoporosis such as postmenopausal osteoporosis, glucocorticoid-inducedosteoporosis, or male osteoporosis, treating osteoarthritis, oraccelerating the rate or improving the outcome of bone fracture healing,wherein said methods utilize one or more of the detection, measurement,removal, purification, or storage methods provided herein. For example,methods of treatment are provided that comprise measuring the actual orrelative amount of abaloparatide related peptides in an abaloparatideformulation prior to administering the formulation to a subject, whereinthe formulation is only administered to the subject if the actual orrelative amount of abaloparatide related peptides are at or below apredetermined threshold value. In another example, methods of treatmentare provided that utilize an abaloparatide formulation stored accordingto the storage methods provided herein, optionally wherein theabaloparatide formulation is subjected to one or more of the detection,measurement, removal, or purification methods provided herein prior tostorage, after storage, and/or at one or more timepoints during storage,for example just before the first administration or a subsequentadministration of the formulation. In certain embodiments, methods areprovided for treating a patient with an abaloparatide formulationcomprising administering a first dosage of abaloparatide formulationthat has been stored for a first period of about 0-23 or about 0-35months at about 2-8° C., then storing the remaining abaloparatideformulation at room temperature, e.g., 20-25° C., for a second period ofabout 30 days or 30 days. In certain embodiments, these methods mayutilize a multi-injection pen, and the pen is stored at room temperaturefor about 30 days (or 30 days) after the first administration, with thesubject receiving one injection per day over that period and in someembodiments the daily dosage of abaloparatide is 80 In certainembodiments, the formulation is administered at approximately the sametime each day, such that dosages are administered about 24 hours apart.In some embodiments the patient discards the multi-injection pen after30 days from the first injection (after a total of up to 30 once dailyinjections).

Provided herein in certain embodiments are methods of treating acondition in a subject in need thereof, e.g., a method of treatingosteoporosis such as post-menopausal osteoporosis,glucocorticoid-induced osteoporosis, or male osteoporosis, a method oftreating osteoarthritis, or, and/or accelerating the rate or improvingthe outcome of bone fracture healing, using a formulation providedherein. In certain embodiments, these methods incorporate one or more ofthe detection, measurement, removal, purification, or storage methodsprovided herein. In certain embodiments, the abaloparatide formulationis administered once daily for about 30 days. In certain embodiments ofthe methods of treatment provided herein, the abaloparatide formulationis administered via subcutaneous injection, for example toperiumbilicular region.

In general and unless stated otherwise, when percentages and percentranges and percent limits are given for abaloparatide, impurities,degradants, the values are determined from HPLC and/or UPLC integrationratios where such HPLC and/or UPLC integration procedures are calibratedin accord with standard techniques known to one of ordinary skill in theart. A percentage of peptide impurities or degradants and/orabaloparatide are derived from the ratio of the particular impurityand/or degradant and/or abaloparatide divided by the total area of thetotal peptide content in the chromatogram (and multiplied by 100%), andthe sum total of all peptide content from an abaloparatide-containingAPI or aqueous formulation should equal about 100%.

In certain embodiments of the methods of treatment provided herein, amulti-dose injection pen is used to administer the drug. In certain ofthese embodiments, the multi-dose injection pen is stored according tothe methods of storage provided herein. In certain embodiments, themulti-dose injection pen initially contains enough formulatedabaloparatide drug product to allow for about 30 days of once dailyinjections, for example at a daily dosage of about 80 μg abaloparatide.For example, the pen may initially contain 2.4 mg or more ofabaloparatide. In certain embodiments, the multi-dose injection pen maycontain about 1.2 mL of formulated abaloparatide drug product at aconcentration of about 2.0 mg/mL. In other embodiments, themulti-injection pen may contain more than enough formulatedabaloparatide drug product for 30 days of once daily injections. Forexample, the pen may initially contain about 3.12 mg abaloparatide. Incertain embodiments, the pen may contain about 1.56 mL of formulatedabaloparatide drug formulation at an abaloparatide concentration ofabout 1.8-2.2 mg/mL, 1.86-2.10, 1.90-2.10 or about 2 mg/mL. In certainof these embodiments wherein the pen contains excess abaloparatideformulation for 30 days of once daily injections, the pen maynonetheless be indicated for disposal at the end of 30 days at roomtemperature. In certain embodiments, the injection pen is disposed after30 days at room temperature regardless of how many injections (up to 30)have been administered and in certain embodiments the disposed pen stillcontains some aqueous formulated abaloparatide.

BRIEF DESCRIPTION OF THE DRAWINGS

This application contains at least one drawing executed in color. Copiesof this application with color drawing(s) will be provided by the Officeupon request and payment of the necessary fees.

FIG. 1A: Rearrangement of Asp residue at position 10 of abaloparatide togenerate beta-Asp10 abaloparatide.

FIG. 1B: Rearrangement of Asp residue at position 10 of abaloparatide togenerate cyclo-Asp10 abaloparatide.

FIG. 1C: Rearrangement of Asp residue at position 17 of abaloparatide togenerate cyclo-Asp17.

FIG.2: Typical HPLC chromatogram of an abaloparatide sample (aqueousformulation at t=0) of abaloparatide using Method 1 (mobile phase ofTFA, acetonitrile, and chromatography water).

FIG. 3: Representative chromatogram from buffered LC run showing thebeta-Asp10 impurity (RRT approximately 0.97 relative to abaloparatide(large peak)).

FIG. 4: Chromatogram from buffered LC of a chemically degraded(resolution test standard) abaloparatide aqueous formulation.

FIG. 5: Typical chromatogram from Method 2 for a resolution standardsolution.

FIG. 6: Typical chromatogram from Method 2 for abaloparatide (aqueousformulation, t=0).

FIG. 7: Formation of beta-Asp10 abaloparatide from abaloparatide analogplotted against time.

FIG. 8: Arrhenius plot of beta-Asp10 formation.

FIGS. 9A-9C: Chromatograms from Method 4. (FIG. 9A) Resolution standardsolution. (FIG. 9B) Overlay spiked truncated peptides with unspikedabaloparatide sample. (FIG. 9C) Beta-Asp10 isomer peak (RDS-001-A01)resolved from abaloparatide in API abaloparatide reference standard.

FIGS. 10A-10B: Formulated abaloparatide drug product chromatograms.(FIG. 10A) Formulated drug product batch analysis (BEJH09b) by Method 1.(FIG. 10B) Formulated drug product batch analysis (BEJH09b) by Method 3.

FIGS. 11A-11B: Testing of API sample 8AK1 by Methods 1 and 2. (FIG. 11A)Testing of API sample 8AK1 by Method 1. (FIG. 11B) Testing of API sample8AK1 by Method 2.

FIGS. 12A-12U: Optimization of Method 4. (FIG. 12A) Truncated peptidesby UPLC conditions related to Method 4: phosphate/C18. Partiallyresolved abaloparatide and ATP (3-34) and ATP (4-34). (FIG. 12B)Truncated peptides by phosphate/C18. Resolved but peak broadenedabaloparatide and ATP (3-34) and ATP (4-34). (FIG. 12C)+55° C. (FIG.12D)+60° C. (FIG. 12E)+65° C. (FIG. 12F)+70° C. (FIG. 12G)+75° C. (FIG.12H)+80° C. (FIG. 121)+85° C. (FIG. 12J)+90° C. (FIG. 12K) Overlay +55°C. (red) and +90° C. (black). (FIG. 12L) Optimization of C18 conditions.(FIG. 12M) Truncated peptides by Method 4 using C8 column. (FIG. 12N)Truncated peptides by phosphate/C4. Blue: Abaloparatide API spiked withRDS-001405. Red: Abaloparatide API spiked with RDS-001-I06. Black:Abaloparatide API unspiked. (FIG. 12O) UPLC phosphate/C4-8AG1. (FIG.12P) UPLC phosphate/C4—6AG1R. (FIG. 12Q) UPLC phosphate/C4—RDHAG112 Fp1(representative IPC sample). (FIG. 12R) UPLC phosphate/C4—RDHAG112 FpAv(representative IPC sample). (FIG. 12S) UPLC phosphate/C4—RDHAG112FpArr. (FIG. 12T) Phosphate/C4—0.4 ml/min—8AG1. (FIG. 12U)Phosphate/C4—0.3 ml/min—8AG1.

FIGS. 13A-13L: Acid, base, and heat stress results for Methods 1-4.(FIG. 13A) Method 1—Acid stress HCl 1N. (FIG. 13B): Method 2—Acid stressHCl 1N. (FIG. 13C) Method 1—Base stress NaOH 0.01N. (FIG. 13D) Method 2—Base stress NaOH 0.01N. (FIG. 13E) Method 1—Heat stress+80° C. (FIG.13F) Method 2 —Heat stress+80° C. (FIG. 13G) Method 3 —Acid Stress HCl1N. (FIG. 13H) Method 4 —Acid Stress HCl 1N. (FIG. 13I) Method 3 —BaseStress NaOH 0.01N. (FIG. 13J) Method 4 —Base Stress NaOH 0.01N. (FIG.13K) Method 3 —Heat stress+80° C. (FIG. 13L) Method 4 —Heat stress+80°C.

DETAILED DESCRIPTION

The following description of the invention is merely intended toillustrate various embodiments of the invention. As such, the specificmodifications discussed are not to be construed as limitations on thescope of the invention. It will be apparent to one skilled in the artthat various equivalents, changes, and modifications may be made withoutdeparting from the scope of the invention, and it is understood thatsuch equivalent embodiments are to be included herein.

Abbreviations

API: active pharmaceutical ingredient; DP: drug product; HPLC: highperformance liquid chromatography; MS: mass spectroscopy; NLT: not lessthan; NMT: not more than; RRT: relative retention time; RT: roomtemperature; TFA: trifluoroacetic acid; and UPLC: ultra-high performanceliquid chromatography.

Definitions

The term “abaloparatide” as used herein refers to [Glu^(22,25),Leu^(23,28,31) Aib²⁹, Lys^(26,30)]hPTHrP(1-34)NH₂)(Ala-Val-Ser-Glu-His-Gln-Leu-Leu-His-Asp-Lys-Gly-Lys-Ser-Ile-Gln-Asp-Leu-Arg-Arg-Arg-Glu-Leu-Leu-Glu-Lys-Leu-Leu-Aib-Lys-Leu-His-Thr-Ala,SEQ ID NO:1), a peptide analog of PTHrP(1-34). Each of the 34 aminoacids in abaloparatide are alpha amino acids. Aib is 2-aminoisobutyricacid, also known as a-aminoisobutyric acid or dimethylglycine.

The terms “beta-Asp-abaloparatide,” “beta-Asp10,” “beta isomer,” and“(beta-Asp10) abaloparatide” as used herein refer to an isomer ofabaloparatide in which the Asp at position 10 (Asp10) has beenisomerized to beta Asp: [b-Asp¹⁰, Glu^(22,25), Leu^(23,28,31), Aib²⁹,Lys^(26,30)]hPTHrP(1-34)NH2)(Ala-Val-Ser-Glu-His-Gln-Leu-Leu-His-b-Asp-Lys-Gly-Lys-Ser-Ile-Gln-Asp-Leu-Arg-Arg-Arg-Glu-Leu-Leu-Glu-Lys-Leu-Leu-Aib-Lys-Leu-His-Thr-Ala,SEQ ID NO:2). FIG. 1A shows a comparison of abaloparatide fragment(8-11) and (beta-Asp10) abaloparatide fragment (8-11).

The terms “cyclo-Asp10” and “(cyclo-Asp10) abaloparatide” as used hereinrefer to an isomer of abaloparatide in which the Asp at position 10(Asp10) has been cyclized to form an imide. The terms “cyclo-Asp17” and“(cyclo-Asp17) abaloparatide” as used herein refer to an isomer ofabaloparatide in which the Asp at position 17 (Asp17) has been cyclizedto form an imide. FIGS. 1B and 1C show comparisons of abaloparatide(8-11) with (cyclo-Asp10) abaloparatide (8-11), and abaloparatide(16-19) with (cyclo-Asp17) abaloparatide (16-19)), respectively.

The term “abaloparatide API” as used herein refers to an abaloparatideformulation that has undergone final manufacture and purification of thepeptide, but has not yet been formulated in an aqueous vehicle suitablefor drug delivery. In certain embodiments, the abaloparatide APIcontains only abaloparatide, or, i.e., there are no significantadditional or added components.

The term “formulated abaloparatide drug product” as used herein refersto an abaloparatide formulation in which the abaloparatide API has beenformulated in an aqueous vehicle suitable for drug delivery.

The term “abaloparatide formulation” as used herein refers to an API orformulated drug product comprising abaloparatide. Such a formulation maycomprise one or more additional components, including both active (e.g.,additional therapeutic agents) and inactive (e.g., excipients, buffers,etc.) components.

The term “about” as used herein with regard to a stated value meanswithin 10% of the stated value.

The term “essentially” as used herein with regard to a stated valuemeans within 5% of the stated value.

The terms “truncated abaloparatide (3-34)” and “truncated abaloparatide(4-34)” (abbreviated herein as “ATP(3-34)” and “ATP(4-34),”respectively) refer to abaloparatide sequences wherein the first two(i.e., Ala-Val) or three (i.e., Ala-Val-Ser) N-terminal amino acids,respectively, are missing.

Description

Abaloparatide is currently in clinical trials for the treatment ofosteoporosis in postmenopausal women. Two different dosage forms arecurrently under development, a subcutaneous (SC) formulation(abaloparatide-SC) for self-injection via a multi-dose injector pen anda transdermal (TD) formulation (abaloparatide-TD) for delivery via amicroneedle patch. For the abaloparatide-SC formulation, the recommendeddosage is 80 μg once daily for a total continuous duration of 18 months.

As disclosed herein, it has been discovered that under certainconditions, abaloparatide can undergo an intramolecular rearrangementthat results in formation of the beta-Asp10 isomer. Numerous batches ofabaloparatide API, mixtures, and formulations had been evaluatedpreviously using a variety of techniques, but none of those techniqueshad identified the presence of the (beta-Asp10) isomer. As discussed indetail in the Examples section below, the existence of the (beta-Asp10)isomer was discovered through application of new particular liquidchromatography separation and purification methods. Some of these newchromatography methods resulted in remarkably clean baseline ornear-baseline separation between abaloparatide and the (beta-Asp10)isomer, as well as other abaloparatide-related impurities such ascyclo-Asp10, cyclo-Asp17, ATP(3-34), and ATP(4-34). The fortuitousidentification and subsequent isolation and characterization of(beta-Asp10) isomer has allowed for the development of improved methodsof storing, analyzing, controlling and administering abaloparatide.

Accordingly, provided herein in certain embodiments are (beta-Asp10)abaloparatide, as well as compositions, pharmaceutical formulations, andkits comprising (beta-Asp10) abaloparatide. In certain embodiments,compositions and pharmaceutical formulations comprising (beta-Asp10)abaloparatide and abaloparatide in predetermined and established ranges.In addition, provided herein are methods of analyzing a sample ofabaloparatide for the presence of (beta-Asp10) abaloparatide. Alsoincluded are the use of (beta-Asp10) abaloparatide in analytic methodsused for the detection of (beta-Asp10) abaloparatide in lots ofabaloparatide API and/or aqueous formulated abaloparatide. Furthermore,(beta-Asp10) abaloparatide is provided as a composition per se, forexample, a material sample comprising >50% byweight, >60%, >70%, >80%, >90%, >95% (beta-Asp10) abaloparatide. Incertain embodiments of this invention, an abaloparatide (beta-Asp10)sample is provided wherein said sample comprises also abaloparatidewherein the sample is w/w (beta-Asp10) abaloparatide toabaloparatide >50% by weight, >60%, >70%, >80%, >90%, >95%,respectively. Compositions of (beta-Asp10) have utility for analyticaldeterminations but also are active per se as an agonist on PTH receptorsproviding credible evidence of utility for use in the treatment ofosteoporosis, as a standalone treatment or in combination with one ormore other drugs. For example, also included are embodiments providingmethods of treating osteoporosis comprising the administration ofabaloparatide together with (beta-Asp10) abaloparatide in apredetermined range. Also included are embodiments wherein a method oftreating osteoporosis is provided comprising a first step of analyzing alot of abaloparatide for the presence of beta-Asp10 and if said lot hasbeta-10Asp in a concentration ≤5%, or between 0.01% and ≤5% thenproceeding to administer 80 μG of abaloparatide to a subject in needthereof.

As described herein, it has been discovered that the ratio ofabaloparatide to (beta-Asp10) isomer within an abaloparatide formulationcan be affected by a number of factors. These factors include, but arenot limited to: (1) purity of original abaloparatide manufacturing lot(i.e., the presence and amount of any beta-Asp10 isomer in the originalabaloparatide lot); and (2) storage conditions, e.g., storagetemperature of abaloparatide formulation(API, aqueous drug formulation),and storage time at particular temperatures.

Provided in certain embodiments of the disclosure are abaloparatide APIsamples comprising ≤0.5% (beta-Asp10) abaloparatide of the total peptidecontent. Provided in certain embodiments of the disclosure areabaloparatide API samples comprising ≤1.0% ATP(3-34) plus ATP(4-34) ofthe total peptide content. Provided in certain embodiments of thedisclosure are abaloparatide API samples comprising ≤0.5% w/w(beta-Asp10) abaloparatide and <1% ATP(3-34) plus ATP(4-34) of the totalpeptide content. Provided in certain embodiments of the disclosure areabaloparatide API samples comprising ≤0.5% beta-Asp10, ≤0.5%cyclo-Asp10, ≤0.5% cyclo-Asp17 and where ATP(3-34) and ATP(4-34) aretogether ≤1.0% of the total peptide content and wherein said API furthercomprises ≥97% of abaloparatide of the total peptide content in the API.In some embodiments, the API is stored at −20±2° C.

Provided in certain embodiments of the disclosure are aqueousabaloparatide formulations comprising ≤1.0% w/w (beta-Asp10), ≤0.5%ATP(3-34), ≤0.5% ATP(4-34), ≤0.5%(cyclo-Asp10), and ≤0.5% (cycloAsp17)of the total peptide content, and an aqueous buffer having a pH of from4.5-5.5, wherein said formulation has an abaloparatide concentration ofbetween about 1.8 mg/mL and about 2.2 mg/mL, between about 1.86 andabout 2.10 mg/mL, between about 1.90 mg/mL and about 2.10 mg/mL, orabout 2.0 mg/mL.

Provided in certain embodiments of the disclosure are aqueousformulations of abaloparatide comprising ≤1.0% beta-Asp10, ≤0.5%cyclo-Asp10, ≤0.5% cyclo-Asp17, ≤0.5% ATP(3-34) and ≤0.5% ATP(4-34) ofthe total peptide content and wherein said aqueous further comprises≥97% of abaloparatide of the total peptide content in the aqueousabaloparatide formulation at t=0 (upon initial formulation of the APIinto an aqueous formulation).

In certain embodiments, the aqueous abaloparatide formulations disclosedherein are stored for 0-23 months or 0-35 months, at 2-8 ° C., and about0-1 month at room temperature, e.g., 20-25° C. or about 25±2° C., thatcomprise abaloparatide and beta-Asp10, and in certain of theseembodiments beta-Asp10 represents ≤5% or between 0% to ≤5%, 0 to 4%, 0to 3%, or 0.1% to 5%, or 0.5% to 4.5%, or 0.5% to 4.0%, or 0.1% to ≤5%,0.5% to ≤5%, or 1.0% to ≤5% % of total peptide content in theformulation. In certain embodiments, the aqueous abaloparatideformulations disclosed herein are stored for 0-23 months or 0-35 months,at 2-8° C., and for about 0-1 month at room temperature, e.g., 20-25° C.or about 25±2° C. that also comprise cyclo-Asp10 and/or cyclo-Asp17and/or ATP(3-34) and/or ATP(4-34), and in certain of these embodimentseach of said cyclo-Asp10, cyclo-Asp17, ATP(3-34) and ATP(4-34) ispresent in an amount of ≤0.5% of peptide content in the formulation. Insome embodiments, the abaloparatide content is ≥93% of the total of thepeptide content in the aqueous abaloparatide formulations.

Provided in certain embodiments of the disclosure are abaloparatideaqueous formulations comprising abaloparatide and ≤0.5% w/w (beta-Asp10)abaloparatide and <1% ATP(3-34) plus ATP(4-34) of the total peptidecontent. In certain embodiments, the abaloparatide aqueous formulationshas an abaloparatide concentration between about 1.8 and about 2.2mg/mL. In certain embodiments, the abaloparatide aqueous formulationshas a pH between about 2 to about 7, about 3 to about 6, about 4 toabout 6, about 4.5 to about 5.5, about 4.7 to about 5.5, about 5.1, orabout 5.2. In certain embodiments, the abaloparatide aqueous formulationcomprises a buffer. Examples of the buffer include, without limitation,an acetate buffer comprising, e.g., acetic acid or sodium acetate; and aphosphate buffer comprising, e.g., potassium phosphate. In certainembodiments, the buffer is in a concentration range sufficient toprovide the desired level of buffer capacity, for example about 0.1 mMto about 60 mM, about 0.5 mM to about 50 mM, about 1 to about 10 mM,about 4 to about 8 mM, or about 6 mM. The abaloparatide aqueousformulations may further comprise an antimicrobial agent (e.g., acompound with a phenolic group such as chlorocresol or phenol) at aconcentration sufficient to provide anti-microbial effect. In certainembodiments, the antimicrobial agent may be phenol at a concentration of≤8.0 mg, for example ≤5.0 mg/mL or about 5.0 mg/mL. In certainembodiments, the antimicrobial agent further serves as an antioxidantpreservative, increasing the integrity of abaloparatide in theformulation by reducing the rate of decomposition over the shelf-life ofthe formulation, for example over 23 months at 2 to 8° C. followed by 1month at 20-25° C. or about 25±2° C., or over 35 months at 2 to 8° C.)followed by 1 month at 20-25° C. or about 25±2° C. In certainembodiments, the antimicrobial agent may increase the integrity ofabaloparatide in the formulation over longer time periods or widertemperature ranges. In certain embodiments, the antioxidant effect maybe more measurably demonstrable over increased storage times, elevatedtemperatures, or other formulation variables

Provided in some embodiments of this disclosure are methods of analyzingan abaloparatide API sample or an abaloparatide aqueous formulationdisclosed herein comprising using a HPLC and/or UPLC. In certainembodiments, the analyzing method comprises using a mobile phasecomprising an aqueous base (e.g., an aqueous buffer). The pH of theaqueous buffer may be about 6 to about 10, about 7 to about 9, about 7.5to about 8.5, about 7.6 to about 8.0 or about 7.8. In certainembodiments, the pH of the aqueous buffer is at RT or about 25 ° C. Theaqueous buffer may comprise phosphate, sulfonate, or combinationsthereof. The aqueous buffer may comprise one or more cationiccounterions such as Na⁺, K⁺, NH₄ ⁺, and combinations thereof. In certainembodiments, the aqueous buffer is ammonium phosphate buffer. In certainembodiments, the aqueous buffer comprises NH₄H₂PO₄ and/or NaH₂PO₄. Incertain embodiments, the analyzing method uses predominately binarymobile phases, e.g., two mobile phases togethercomprise >90%, >95%, >98%, or >99% v/v of the mobile phase. In certainembodiments, one mobile phase is an aqueous mobile phase, and one mobilephase is an organic mobile phase comprising, e.g., acetonitrile and/ormethanol. In certain embodiments, the mobile phases further comprise athird mobile phase (e.g., one solvent or combination of solvents) thatis ≤10% v/v of the mobile phase. By way of non-limiting example, apredominately binary solvent system could contain 60% water, 30%acetonitrile, and up to 10% another solvent or combination of othersolvents, e.g., 10% methanol, 5% methanol and 5% ethanol, or any othercombination that meets the necessary guidelines. In certain embodiments,the above conditions are used in an UPLC system. In certain embodiments,the analyzing method comprises using a Cx-Silicon based reversed phasecolumn. In certain embodiments, x is 4, 8, or 16. In certainembodiments, the carbon components of the column are 16 carbons, 8carbons or 4 carbons in linear length. In certain embodiments, thelinear chain is further branched with varying alkyl groups (e.g.,isopropyl). In certain embodiments, the UPLC utilizes a columncontaining average mean particle diameters of less than 3.0 microns, orless than 2.5 microns, or less than 2.0 microns. In certain embodiments,the column temperature is above RT, e.g., about 40 to about 90° C.,about 40 to about 80° C., about 40 to about 70° C., about 40 to about60° C., about 40° C., about 45° C., about 50° C., about 55° C., or about60° C.

Provided in some embodiments of this disclosure are methods of analyzingan abaloparatide formulation for use in treating patients comprising:

-   -   (a) storing an aqueous abaloparatide formulation initially        comprising ≤1.0% w/w (beta-Asp10), ≤0.5% ATP(3-34), ≤0.5%        ATP(4-34), ≤0.5%(cyclo-Asp10), and ≤0.5% (cycloAsp17) of the        total peptide content, an aqueous buffer having a pH of from        4.5-5.5, and an abaloparatide concentration of between 1.8 mg/mL        and 2.2 mg/mL, for a first period of 23 months at between        2-8° C. and a second period of 1 month at 20-25° C., optionally        25±2° C., and    -   (b) analyzing said formulation by an analyzing method disclosed        herein. For example, using HPLC and/or UPLC with a mobile phase        comprising an aqueous phase and a buffer.

Provided in some embodiments of this disclosure are methods of treatinga subject (e.g., human) with an abaloparatide formulation disclosedherein comprising (a) a first subcutaneous administration to theperiumbilical area using a multi-dose injector pen, (b) a second andsubsequent once-daily subcutaneous administrations to the periumbilicalarea using the same injector pen, wherein the subsequent administrationscontinue until 30 days has passed from the first administration, whereinsaid injector pen is stored at 20-25° C. from the first administrationto the end of the 30 day administration period, and wherein the first,second, and subsequent administration all utilize the same dosage. Incertain embodiments, said injector pen is discarded after the 30 dayperiod. In certain embodiments, said dosage is about 80 μgabaloparatide. In certain embodiments, said abaloparatide formulationcomprises a buffer. In certain embodiments, said abaloparatideformulation has a pH of about 4.5 to about 5.5. In certain embodiments,the second and subsequent administrations occur at approximately thesame time of day as the first administration. In certain embodiments,the administration site is varied each day to different sites within theperiumbilicular area. In certain embodiments, the subject hasosteoporosis. In certain embodiments, the subject has severeosteoporosis. In certain embodiments, the subject is a postmenopausalwoman at high risk for fracture. In certain embodiments, the subject hasa history of osteoporotic fracture and/or multiple risk factors forfracture or who have failed or are intolerant of previous osteoporosistherapy.

Provided in some embodiments of this disclosure are methods ofincreasing bone mineral density in the hip, wrist, femoral neck or spineof a patient with osteoporosis comprising the administration ofabaloparatide according to the treating methods disclosed herein.

Provided in some embodiments of this disclosure are methods ofincreasing bone mass in a male subject with primary or hypogonadalosteoporosis who are at high risk for fracture comprising theadministration of abaloparatide according to the treating methodsdisclosed herein. In certain embodiments, the male subject has a historyof osteoporotic fracture, or multiple risk factors for fracture, or hasfailed or are intolerant to previous osteoporosis therapy.

Provided herein in certain embodiments are methods of treating acondition in a subject in need thereof, e.g., a method of treatingosteoporosis such as postmenopausal osteoporosis, glucocorticoid-inducedosteoporosis, or male osteoporosis, treating osteoarthritis, oraccelerating the rate or improving the outcome of bone fracture healing,wherein said methods utilize one or more of the detection, measurement,removal, purification, or storage methods provided herein. For example,methods of treatment are provided that comprise measuring the actual orrelative amount of abaloparatide related peptides in an abaloparatideformulation prior to administering the formulation to a subject, whereinthe formulation is only administered to the subject if the actual orrelative amount of abaloparatide related peptides are at or below apredetermined threshold value. In another example, methods of treatmentare provided that utilize an abaloparatide formulation stored accordingto the storage methods provided herein, optionally wherein theabaloparatide formulation is subjected to one or more of the detection,measurement, removal, or purification methods provided herein prior tostorage, after storage, and/or at one or more timepoints during storage,for example just before the first administration or a subsequentadministration of the formulation. In certain embodiments, methods areprovided for treating a patient with an abaloparatide formulationcomprising administering a first dosage of abaloparatide formulationthat has been stored for a first period of about 0-23 or about 0-35months at about 2-8° C., then storing the remaining abaloparatideformulation at room temperature, e.g., 20-25° C., for a second period ofabout 30 days or 30 days. In certain embodiments, these methods mayutilize a multi-injection pen, and the pen is stored at room temperaturefor about 30 days (or 30 days) after the first administration, with thesubject receiving one injection per day over that period and in someembodiments the daily dosage of abaloparatide is 80 In certainembodiments, the formulation is administered at approximately the sametime each day, such that dosages are administered about 24 hours apart.In some embodiments the patient discards the multi-injection pen after30 days from the first injection (after a total of up to 30 once dailyinjections).

Provided herein in certain embodiments are methods of treating acondition in a subject in need thereof, e.g., a method of treatingosteoporosis such as post-menopausal osteoporosis,glucocorticoid-induced osteoporosis, or male osteoporosis, a method oftreating osteoarthritis, or , and/or accelerating the rate or improvingthe outcome of bone fracture healing, using a formulation providedherein. In certain embodiments, these methods incorporate one or more ofthe detection, measurement, removal, purification, or storage methodsprovided herein. In certain embodiments, the abaloparatide formulationis administered once daily for about 30 days. In certain embodiments ofthe methods of treatment provided herein, the abaloparatide formulationis administered via subcutaneous injection, for example toperiumbilicular region.

In certain embodiments of the methods of treatment provided herein, amulti-dose injection pen is used to administer the drug. In certain ofthese embodiments, the multi-dose injection pen is stored according tothe methods of storage provided herein. In certain embodiments, themulti-dose injection pen initially contains enough formulatedabaloparatide drug product to allow for about 30 days of once dailyinjections, for example at a daily dosage of about 80 μg abaloparatide.For example, the pen may initially contain 2.4 mg or more ofabaloparatide. In certain embodiments, the multi-dose injection pen maycontain about 1.2 mL of formulated abaloparatide drug product at aconcentration of about 2.0 mg/mL. In other embodiments, themulti-injection pen may contain more than enough formulatedabaloparatide drug product for 30 days of once daily injections. Forexample, the pen may initially contain about 3.12 mg abaloparatide. Incertain embodiments, the pen may contain about 1.56 mL of formulatedabaloparatide drug formulation at an abaloparatide concentration ofabout 1.8-2.2 mg/mL, 1.86-2.10, 1.90-2.10 or about 2 mg/mL. In certainof these embodiments wherein the pen contains excess abaloparatideformulation for 30 days of once daily injections, the pen maynonetheless be indicated for disposal at the end of 30 days at roomtemperature. In certain embodiments, the injection pen is disposed after30 days at room temperature regardless of how many injections (up to 30)have been administered and in certain embodiments the disposed pen stillcontains some aqueous formulated abaloparatide.

Provided in some embodiments of this disclosure are methods ofestablishing suitability of an abaloparatide manufacturing process andabaloparatide aqueous formulation comprising formulating abaloparatideAPI into an aqueous vehicle, wherein said abaloparatide API is firstanalyzed and determined to contain ≤0.5% beta-Asp10, ≤0.5% cyclo-Asp10,≤0.5% cyclo-Asp17 of the total peptide content and where ATP(3-34) andATP(4-34) are together ≤1.0% of the total peptide and wherein said APIfurther comprises ≥97% of abaloparatide of the total peptide content inthe API and further determining that the initially prepared aqueousabaloparatide containing formulation (t=0) comprises ≤1.0% beta-Asp10,≤0.5% cyclo-Asp10, ≤0.5% cyclo-Asp17, ≤0.5% ATP(3-34) and ≤0.5%ATP(4-34) of the total peptide and wherein said aqueous furthercomprises ≥97% of abaloparatide of the total peptide content in theaqueous abaloparatide formulation and further embodiments, storing saidaqueous abaloparatide formulations for 23 months and then storing at25±2° C. for 1 month or 35 months and then storing at 25±2° C. for 1month at 2-8° C. and then storing at 25±2° C. for 1 month and evaluatingthe drug product during and after said storage period and in certain ofthese embodiments each of said cyclo-Asp10, cyclo-Asp17, ATP(3-34) andATP(4-34) is present in an amount of ≤0.5% of peptide content in theformulation and the abaloparatide content is ≥93% of the total of thepeptide content in the sample. The following examples are provided tobetter illustrate the claimed invention and are not to be interpreted aslimiting the scope of the invention. To the extent that specificmaterials or methods are mentioned, they are merely for purposes ofillustration and are not intended to limit the invention. One skilled inthe art may develop equivalent means without the exercise of inventivecapacity and without departing from the scope of the invention. It willbe understood that many variations can be made in the procedures hereindescribed while still remaining within the bounds of the presentinvention. It is the intention of the inventors that such variations areincluded within the scope of the invention.

EXAMPLES Example 1 Identification of beta-Asp10 in Samples ContainingAbaloparatide

The presence of (beta-Asp10) isomer in abaloparatide API, mixtures, andformulations was unexpectedly discovered using modifications topre-existing liquid abaloparatide chromatography methods. It was foundthat resolution of the (beta-Asp10) abaloparatide peak could beaccomplished with certain buffer systems using HPLC or UPLC.Identification and isolation of (beta-Asp10) abaloparatide isomer wascomplicated by the fact that the buffer system needed to resolve themixture was incompatible with mass spectroscopy (MS), while the eluentsolvent system that was compatible with MS was unable to resolve theisomer from its parent. This led to the development of a method wherebybeta-Asp10 was separated from abaloparatide using HPLC with bufferembodiments described herein. Since MS coupled to the HPLC could not beused with the buffer, a physical quantity of beta-Asp10 was isolated andits structure was elucidated with MS and peptide degradation, andfinally by comparison to a prepared sample of the beta-Asp10 isomer.Accordingly, the combined use of HPLC and UPLC with a phosphate bufferallowed for both the identification and optimization of chromatographyanalyses including the identification of several enumeratedabaloparatide related impurities and/or degradants.

In order to understand the results obtained, (Methods 1-4 describedbelow) comprising two different mobile phases (buffer and no buffer)applied to both an HPLC system and an UPLC system will be juxtaposed anddiscussed in detail below.

Method I: HPLC Using a Binary Solvent System with Trifluoroacetic Acid(TFA) to Analyze a Sample of Abaloparatide API.

Solubilization solvent (0.1N acetic acid) was prepared by adding 3.00g±0.05 of acetic acid 100% to a 500 mL volumetric flask, bringing tovolume with processed water, and sonicating for two minutes.

Mobile phase A (0.1% TFA (HPLC grade or equivalent) in processed water)was prepared by introducing about 900 mL processed water in a 1.0 Lvolumetric flask, then adding 1.0 mL TFA and bringing to volume withprocessed water. Mobile phase B (0.1% TFA in processedwater/acetonitrile 20/80) was prepared by introducing 800 mLacetonitrile (HPLC grade), in a 1.0 L flask, then adding 200 mLprocessed water and 1.0 mL TFA (HPLC grade). Both mobile phases weresonicated for two minutes. If necessary for longer analyses, largerquantities of mobile phase were prepared by multiplying the weights andvolumes above.

Test (actual test sample) and reference standard solutions were preparedusing an analytical balance with a minimum weight of at least 5.0 mg.For test solution, 5.0 to 6.0 mg of abaloparatide API test sample wasadded to a clean vial and dissolved in the solubilization solvent toobtain a 1.0 mg/mL solution. Two sample solutions were prepared. Forreference standard solution, 5.00 to 6.00 mg of abaloparatide APIreference standard was added to a clean vial and dissolved insolubilization solvent to obtain a 1.00 mg/mL solution. Two referencestandard solutions were prepared. The water content of the referencestandard was determined on the same day as sample analysis. The samecontainer was used for both water and abaloparatide API contentdetermination. Identification admixture was prepared by mixing 250 μL ofreference solution and 250 μL of test sample solution.

This method utilized a Zorbax 300SB C8 5 μm 250×4.6 mm AgilentTechnologies #880995-906 (or equivalent) analytical HPLC column, and aliquid chromatographic system capable of gradient elution, e.g., anAgilent Series 1100 or equivalent, equipped with the following:

-   -   Pumps, column oven, Waters on-line mixer cat #WAT051518 (or        equivalent) for baseline noise reduction;    -   Variable volume sample injector;    -   Thermostated sample injector;    -   Variable wavelength UV detector equipped with a standard        flowcell (10 mm, 13 maximum pressure 120 bar); and    -   Electronic integrator device such as Empower CDS or equivalent.

Detection was performed at UV 220 nm. The column temperature was +50° C.and the autosampler temperature was +10° C. The injection volume was 20μL, the flow rate was 0.9 mL/min, and the analysis stop time was 35minutes. Elution conditions are set forth in Table 1.

TABLE 1 Elution conditions of Method 1 Time (min) % mobile phase A %mobile phase B 0.0 71 29 25.0 65 35 35.0 65 35 36.0 71 29 45.0 71 29

The column was equilibrated by passing mobile phase through under thechromatographic conditions as set forth above until a stable baselinewas achieved. The initial mobile phase composition could be adjusted ±1%B or the initial flow rate ±0.1 mL/min, keeping the same gradient slope,in order to obtain a retention time for abaloparatide API of about 18.2minutes ±1 minute.

Five replicates of reference solution were injected for a systemsuitability test. The following parameters should be calculatedaccording to the United States Pharmacopeia and the National Formulary(USP-NF).

-   -   The mean theoretical plates calculated by the CDS according to        Empower standard field EP Plate Count for abaloparatide peak        should be NLT 3000;    -   The mean tailing factor calculated by the CDS according to        Empower standard field USP Tailing for abaloparatide peak should        be NMT 4.5; and    -   RSD % on abaloparatide peak area should be NMT 2.0%.

The injection sequence was as follows:

-   -   Run 1: Baseline (solubilization solvent)    -   Run 2: Reference standard solution (preparation 1- replicate 1)    -   Run 3: Reference standard solution (preparation 1- replicate 2)    -   Run 4: Reference standard solution (preparation 2- replicate 1)    -   Run 5: Test solution (preparation 1)    -   Run 6: Test solution (preparation 2)    -   Run 7: Reference standard solution (preparation 1)    -   Run 8: Reference standard solution (preparation 2- replicate 2)    -   Run 9: Reference standard solution (preparation 2- replicate 3)    -   Run 10: Identification admixture

Runs 2-4 and 7-9 could be skipped when abaloparatide API content was notbeing analyzed. If the identification was not required (e.g., retest,stability studies, . . . ) then Run 10 was not performed. The analyticalsequence bracketed by reference standard solutions (e.g. runs 5-6)should not exceed 8 injections (4 test samples).

Any peaks observed in run 1 were subtracted from sample chromatograms.The peak area reject was set to 0.05% of the mean from the abaloparatidepeak area obtained for the five reference standard injections from thesystem suitability test.

The chromatogram run according to method 1 conditions on the API showeda single significant peak (see FIG. 2).

Sample purity for each test solution chromatogram was calculated by areanormalization % according to the following formula

${{Overall}\mspace{14mu} {Purity}\mspace{11mu} \left( {{{area}\mspace{14mu} \%},{1\mspace{14mu} {decimal}}} \right)} = {\frac{{Peak}\mspace{14mu} {area}\mspace{14mu} {of}\mspace{14mu} {Abaloparatide}}{{Total}\mspace{14mu} {area}\mspace{14mu} {of}\mspace{14mu} {all}\mspace{14mu} {peaks}\mspace{14mu} {in}\mspace{14mu} {the}\mspace{14mu} {chromatogram}} \times 100}$

The level of each impurity in each test solution chromatogram wascalculated by area normalization % according to the following formula

${{Impurity}\mspace{14mu} {level}\mspace{14mu} \left( {{{area}\mspace{14mu} \%},{1\mspace{14mu} {decimal}}} \right)} = {\frac{{Related}\mspace{14mu} {substance}\mspace{14mu} {peak}\mspace{14mu} {area}}{{Total}\mspace{14mu} {area}\mspace{14mu} {of}\mspace{14mu} {all}\mspace{14mu} {peaks}\mspace{14mu} {in}\mspace{14mu} {the}\mspace{14mu} {chromatogram}} \times 100}$

The relative retention time (RRT) of impurities was calculated using thefollowing formula:

${R\; R\; T\mspace{11mu} \left( {2\mspace{14mu} {decimals}} \right)} = \frac{{RT}_{imp}}{{RT}_{Abaloparatide}\mspace{14mu} {in}\mspace{14mu} {the}\mspace{14mu} {same}\mspace{14mu} {chromatogram}}$

where RT_(imp) was retention time of the related impurity in minutes andRT_(abaloparatide) was retention time of the abaloparatide peak inminutes.

Any peak corresponding to an unspecified impurity was reported to onedecimal with its corresponding RRT.

The level of total impurities was calculated using the following formula

Total impurities(area %, decimal)=100−overall purity

The abaloparatide content in each test solution chromatogram wascalculated according to the formula:

${{Abaloparatide}\mspace{14mu} {content}\mspace{14mu} \left( {{w\text{/}w\mspace{14mu} \%},\; {1\mspace{14mu} {decimal}}} \right)} = {\frac{{As} \times {Qr} \times {Cref}}{{Ar} \times {Qs} \times 100} \times 100}$

wherein As was the abaloparatide peak area obtained in the testsolutions, Ar was the mean of abaloparatide peak areas in the sixbracketing injections of reference standard, Qr was the injectedquantity of reference standard (μg), Qs was the injected quantity ofsample (μg), Cref was the abaloparatide content of the referencestandard determined by the formula:

$\frac{\begin{matrix}{\left( {100 - {H_{2}O\mspace{14mu} \left( {\% \mspace{14mu} \frac{w}{w}} \right)} - {{AcOH}\mspace{14mu} \left( {\% \mspace{11mu} \frac{w}{w}} \right)} - {{residual}\mspace{14mu} {TFA}\mspace{14mu} \left( {\% \mspace{11mu} \frac{w}{w}} \right)}} \right) \times} \\{{HPLC}\mspace{14mu} {purity}\mspace{14mu} \left( {{area}\mspace{14mu} \%} \right)}\end{matrix}}{100}$

(content determined on the same day that reference standard solution wasprepared). A typical chromatogram from Method 1 is shown in FIG. 2, andresults are summarized in Table 2.

TABLE 2 % Height Name RT Area Area (μV) Relative_RT 1 RDS0001* 18.2557904259 99.83 187529 1.000 2 21.217 6248 0.08 156 1.162 3 32.955 74660.09 250 1.805 Sum 7917973 *RDS0001 = abaloparatideMethod 2: UPLC Using a Binary Solvent System with TFA to Analyze aSample of Abaloparatide API and a Partially Degraded Test Solution ofAbaloparatide API.

This method utilized a UPLC procedure for evaluating overall purity,major single impurity, and total impurities of abaloparatide, API. Thelevel of purity and impurities in abaloparatide, API were quantitated byarea normalization.

Processed water was filtered through 0.22 in Simplicity Millipore orequivalent. Solvent (processed water/acetonitrile 50/50 (v/v)) wasprepared by adding 140 mL of processed water and 140 mL of UPLC gradeacetonitrile to a 500 mL bottle, homogenizing, and sonicating for twominutes. Mobile phase A2 (0.05% TFA in processed water) was prepared byadding 125 μL of UPLC grade TFA to about 100 mL of processed water in a250 mL volumetric flask and bringing to volume with processed water.Mobile phase B2 (0.05% TFA in processed water/acetonitrile 50/50) wasprepared by adding 125 μL of TFA to about 100 mL of solvent in a 250 mLvolumetric flask and bringing to volume with solvent. Both mobile phaseswere homogenized and sonicated for two minutes. 250 mL of mobile phaseA2 and 250 mL of mobile phase B2 were enough for 80 injections. Ifnecessary for long analyses, larger quantity of mobile phase could beprepared by multiplying weights and volumes required.

Injector weak wash solution was processed water/acetonitrile (90/10),injector strong wash solution was processed water/acetonitrile (10/90).HCl 0.5N was prepared by adding 4.1 mL of HCl 37% to about 50 mL ofwater in a 100 mL volumetric flask, bringing to volume with processedwater, homogenizing, and sonicating for two minutes.Tris(hydroymethyl)-aminomethane 0.05N (Tris) was prepared by adding 50mL processed water to a 100 mL volumetric flask containing 0.60 g±0.02 gof Tris, bringing to volume with processed water, and homogenizing.

Test and resolution standard solutions were prepared using an analyticalbalance with a minimum weight of at least 5.00 mg in a humiditycontrolled area set to 30%±10% relative humidity. For test solution,5.00 to 6.00 mg of abaloparatide sample was added to a clean vial anddissolved in processed water to obtain a 1.0 mg/mL solution. Two samplesolutions (2-6.2.a and 2-6.2.b) were prepared. For resolution standardsolution (1.0 mg/mL HCl 0.5N buffered with Tris 0.05N), 5.0 to 6.0 mg ofabaloparatide reference standard was added to a clean vial and dissolvedin HCl 0.5N to obtain a 10.0 mg/mL solution. After 90-120 minutesreaction time at +25° C. (RRT 1.02 impurity must be greater than 0.5%and less than 2%), nine volumes of Tris 0.05N were added to obtain a 1.0mg/mL solution. The chromatographic profile must match the graph in FIG.5.

This method utilized a Waters Acquity CSH C18 1.7 μm, 100×2.1 mm UPLCcolumn. Detection was performed at UV 220 nm (20Hz). The columntemperature was +40° C.±2° C. and the autosampler temperature was +10°C.±2° C. The injection volume was 2 μL, the flow rate was 300 μL/min,and the analysis stop time was 14.5 minutes. Elution conditions are setforth in Table 3.

TABLE 3 Elution conditions of Method 2 Time (min) % mobile phase A2 %mobile phase B2 0.0 68 32 0.5 68 32 14.5 40 60 15.0 20 80 15.5 20 8015.6 68 32 18.0 68 32

The initial mobile phase composition may be adjusted, keeping the samegradient slope, in order to obtain abaloparatide retention time between8.5 and 9.5 minutes.

The injection sequence was as follows:

-   -   Run 1: Baseline process water (wash)    -   Run 2: Resolution standard solution    -   Run 3-7: Test solution (preparation 1)    -   Run 8: Baseline process water    -   Run 9: Test solution (preparation 1)    -   Run 10: Test solution (preparation 2)

Runs 2-8 would not be started unless the System Suitability Test (SST)parameters were met.

-   For run #2, the chromatographic profile must match the graph in FIG.    5 with 3 distinct peaks after main peak. The first impurity (RRT    1.02) must be between 0.5% and 2%.-   For runs 2-7, the relative standard deviation (RSD) of abaloparatide    peak area must be <2.0%. and RSD of abaloparatide retention time    must be <2.0%.-   For run 8, the area of any peak with a peak retention time    corresponding to that of abaloparatide must be <2.0% of the mean    peak area from runs 3-7.

Any peaks observed in run 8 were subtracted from sample chromatograms.The peak area reject was set to 0.05% of the mean from the abaloparatidepeak area obtained for the duplicate injections from the sample.

Sample purity for runs 9 and 10 was calculated by area normalization %according to the following formula:

${{Sample}\mspace{14mu} {overall}\mspace{14mu} {purity}\mspace{14mu} \left( {{{area}\mspace{14mu} \%},{1\mspace{14mu} {decimal}}} \right)} = {\frac{{Peak}\mspace{14mu} {area}\mspace{14mu} {of}\mspace{14mu} {Abaloparatide}}{{Total}\mspace{14mu} {area}\mspace{14mu} {of}\mspace{14mu} {all}\mspace{14mu} {peaks}\mspace{14mu} {in}\mspace{14mu} {the}\mspace{14mu} {chromatogram}} \times 100}$

The level of each impurity was calculated by area normalization %according to the following formula:

${{Unspecified}\mspace{14mu} {Impurity}\mspace{14mu} {level}\mspace{14mu} \left( {{{area}\mspace{14mu} \%},{1\mspace{14mu} {decimal}}} \right)} = {\frac{{Related}\mspace{14mu} {substance}\mspace{14mu} {peak}\mspace{14mu} {area}}{{Peak}\mspace{14mu} {area}\mspace{14mu} {of}\mspace{14mu} {all}\mspace{14mu} {peaks}\mspace{14mu} {in}\mspace{14mu} {the}\mspace{14mu} {chromatogram}} \times 100}$

The level of total impurities was calculated using the followingformula:

Total impurities(area %, decimal)=100−overall purity

Typical chromatograms from Method 2 are shown in FIG. 5 and FIG. 6.Comparing FIG. 2 using HPLC vs FIG. 5 and FIG. 6 that use UPLC (neitherwith buffer) some additional peaks appear right after the abaloparatide(main) peak in the UPLC method, indicating it has increased resolutioncompared to HPLC. Notably, (b-Asp10) is identified in neither Method 1or Method 2.

Method 3: HPLC Using a Binary Solvent System with Ammonium Phosphate((NH₄)₂PO₄) to Analyze a Sample of Abaloparatide API Against a PartiallyDegraded Test Solution

This method utilized a HPLC procedure for identification, overallpurity, major single impurity, total impurities, and assay determinationof abaloparatide, API. The level of purity and impurities inabaloparatide, API are quantitated by area normalization.

Stock solution 3-5.1 (0.8 M H3PO4 in processed water) was prepared byadding 28 mL of 85% o-phosphoric acid (analytical grade or equivalent)to 200 mL of processed water (MAP-067/187 or equivalent) in a 500 mLvolumetric flask and bringing to volume with processed water. Stocksolution 3-5.2 (320 mM (NH₄)₂HPO₄ in processed water) was prepared byadding 400 mL of stock solution 3-5.1 and 100 mL processed water to a 1liter flask, adjusting the pH to 7.8 using NH₄OH (30% ammonia solutionanalytical grade or equivalent), transferring the solution in avolumetric flask and bringing to 1.0 L with processed water, andsonicating for two minutes.

Mobile phase A (128 mM (NH₄)₂HPO₄ in processed water) was prepared byadding 600 mL of processed water to 400 mL of stock solution 3-5.2 in a1 liter flask and sonicating for two minutes. Mobile phase B ((70% 320mM (NH₄)₂HPO₄/30% processed water)/acetonitrile (50/50)) was prepared byadding 150 mL of processed water and 500 mL of HPLC grade acetonitrileto 350 mL of stock solution 3-5.2 in a 1 liter flask and sonicating fortwo minutes.

For test solution, 9.50 to 10.50 mg of abaloparatide, API test samplewas added to a clean vial and dissolved in processed water to obtain a2.0 mg/mL solution. Two test solutions were prepared. For referencestandard solution, 9.50 to 10.50 mg of abaloparatide, API reference wasadded to a clean vial and dissolved in processed water to obtain a 2.0mg/mL solution. Two reference standard solutions are prepared .Identification admixture was prepared by mixing 250 μL of referencesolution and 250 μL of test sample solution.

For resolution test solution, 9.50 to 10.50 mg of abaloparatide, APIreference standard was added to a clean vial and dissolved in 0.01Nsodium hydroxide to obtain a 4.0 mg/mL solution. This solution washeated at +40° C. for four hours, and then one volume of 0.01Nhydrochloric acid was added to neutralize. Abaloparatide referencestandard and degraded solution (2 mg/mL) were injected successivelyfollowing the method. The appropriate volumes from both solutions weremixed to obtain an area percent content for RRT 1.07 degradationimpurity between 2.0 and 2.5%. The solution was stored at −20° C.

This method utilized an X-Bridge C18 5 μm 150×4.6 mm Waters #186003116(or equivalent) analytical HPLC column, and an HPLC system capable ofgradient elution, e.g., an Agilent Series 1100 or equivalent, equippedwith the following:

-   -   Pumps, column oven, Waters on-line mixer cat #WAT051518 (or        equivalent) for baseline noise reduction;    -   Variable volume sample injector;    -   Thermostated sample injector;    -   Variable wavelength UV detector equipped with a standard        flowcell (10 mm, 13 maximum pressure 120 bar); and    -   Electronic integrator device such as Empower CDS or equivalent.

Detection was performed at UV 214 nm. The column temperature was +60° C.and the autosampler temperature was +15° C. The injection volume was 20the flow rate was 0.8 mL/min, and the analysis stop time was 60 minutes.Elution conditions are set forth in Table 4.

TABLE 4 Elution conditions of Method 3 Time (min) % mobile phase A %mobile phase B 0.0 77 23 12.0 53 47 46.0 53 47 56.0 43 57 58.0 0 10063.0 0 100 65.0 77 23 75.0 77 23

The initial mobile phase composition may be adjusted ±1% B or theinitial flow rate ±0.1 mL/min, keeping the same gradient slope, in orderto obtain a retention time for abaloparatide API between 32 and 36minutes.

The column was equilibrated by passing mobile phase through under thechromatographic condition defined above until a stable baseline wasachieved.

Five replicates of test solution were injected for a system suitabilitytest. The following parameters was calculated according to USP-NF:

-   -   The mean theoretical plates calculated by the CDS according to        Empower standard field EP Plate Count for abaloparatide peak        must be NLT 16000;    -   The mean tailing factor calculated by the CDS according to        Empower standard field USP Tailing for abaloparatide peak must        be NMT 1.8; and    -   RSD % on abaloparatide peak area must be NMT 1.0%.

Resolution test solution was further injected for the system suitabilitytest, and the Empower CDS custom filed “Peak-to-valley-front-ratio” wasused to report the Height/Valley ratio between abaloparatide and RRT1.07 impurity peaks. This ratio should be not lower than 1.43.

The injection sequence was as follows:

-   -   Run 1: Baseline (processed water)    -   Run 2: Reference standard solution (preparation 1 replicate 1)    -   Run 3: Reference standard solution (preparation 1 replicate 2)    -   Run 4: Reference standard solution (preparation 2 replicate 1)    -   Run 5: Test solution (preparation 1)    -   Run 6: Test solution (preparation 2)    -   Run 7: Reference standard solution (preparation 1 replicate 3)    -   Run 8: Reference standard solution (preparation 2 replicate 2)    -   Run 9: Reference standard solution (preparation 2 replicate 3)    -   Run 10: Identification admixture

Runs 2-4 and 7-10 may be skipped when abaloparatide identification andassay are not requested. Identification of abaloparatide is confirmed bythe chromatogram obtained from Run 10 showing a single significant peak.

The individual related substance content and sample purity from Runs 5and 6, excluding any peak observed in Run 1, were determined. Samplepurity for each test solution chromatogram was calculated by areanormalization % according to the following formula:

${{Sample}\mspace{14mu} {overall}\mspace{14mu} {purity}\mspace{14mu} \left( {{{area}\mspace{14mu} \%},{1\mspace{14mu} {decimal}}} \right)} = {\frac{{Peak}\mspace{14mu} {area}\mspace{14mu} {RDS}\text{-}001}{{Peak}\mspace{14mu} {area}\mspace{14mu} {of}\mspace{14mu} {all}\mspace{14mu} {peaks}\mspace{14mu} {in}\mspace{14mu} {the}\mspace{14mu} {chromatogram}} \times 100}$

The level of each impurity was calculated by area normalization %according to the following formula:

${{Impurity}\mspace{14mu} {level}\mspace{14mu} \left( {{{area}\mspace{14mu} \%},{1\mspace{14mu} {decimal}}} \right)} = {\frac{{Related}\mspace{14mu} {substance}\mspace{14mu} {peak}\mspace{14mu} {area}}{{Peak}\mspace{14mu} {area}\mspace{14mu} {of}\mspace{14mu} {all}\mspace{14mu} {peaks}\mspace{14mu} {in}\mspace{14mu} {chromatogram}} \times 100}$

The level of total impurities was calculated using the followingformula:

Total impurities(area %, 1 decimal)=100−overall purity

The assay of abaloparatide was calculated according to the formula:Abaloparatide assay

$\left( {{m\text{/}m\mspace{14mu} \%},{1\mspace{14mu} {decimal}}} \right) = {\frac{{Asample} \times {Qref} \times {CRDS}\text{-}001\; {ref} \times {PRDS}\text{-}001\; {ref}}{{Aref} \times {Qsample} \times 100 \times 100} \times 100}$

wherein Asample was the mean of the abaloparatide peak areas in the twoinjections of test sample, Qref was injected quantity of referencestandard (μg), CRDS-001ref was the abaloparatide peptide content of thereference standard calculated as (100%-% water-% acetic acid),PRDS-001ref was the mean purity (area percent) of the abaloparatide inthe six bracketing injections of reference standard, Aref was the meanof the abaloparatide peak areas in the six bracketing injections ofreference standard (Runs 2-4 and 7-9), and Qsample was the injectedquantity of sample (m). A chromatogram of the partially degradedreference standard using the conditions described is shown in FIG. 4.Method 4: UPLC Using a Binary Solvent System with Ammonium Phosphate((NH₄)₂PO₄) to Analyze a Sample of Abaloparatide API Against a PartiallyDegraded Test Solution

This method utilized a UPLC procedure for identification, overallpurity, individual impurity, total impurities, and content determinationof abaloparatide, API. The level of purity and impurities inabaloparatide, API are quantitated by area normalization.

Stock solution (97 mM (NH₄)₂HPO₄ in processed water) was prepared byadding 5.6 g of 85% phosphoric acid (the same as used in Method 3) to450 mL of processed water (the same as used in Method 2) in a 500 mLbottle, adjusting the pH to 7.8 by adding NH₄OH (the same as used inMethod 3), transferring the solution to a volumetric flask, and bringingto 500 mL volume with processed water.

Mobile phase A2 (39 mM (NH₄)₂HPO₄ in processed water) was prepared byadding 100 mL of stock solution and 150 mL of processed water to a 250mL bottle, mixing, and sonicating for two minutes. Mobile phase B2 ((70%97 mM (NH₄)₂HPO₄/30% processed water)/acetonitrile (50/50)) was preparedby adding 140 mL of stock solution, 60 mL processed water, and 200 mLacetonitrile (the same as used in Method 2) to a 500 mL volumetricflask, mixing, and sonicating for two minutes.

Injector weak wash solution was processed water/acetonitrile (90/10),injector strong wash solution was processed water/acetonitrile (10/90).HCl 1N was prepared by adding 4.1 mL of HCl 37% to about 20 mL of waterin a 50 mL volumetric flask, bringing to volume with processed water,homogenizing, and sonicating for two minutes. HCl 0.01N was prepared byadding 1 mL of HCl 1N to about 20 mL of water in a 100 mL volumetricflask, bringing to volume with processed water, homogenizing, andsonicating for two minutes. NaOH 0.01N was prepared by 1 mL of NaOH 1Nto about 20 mL of processed water in a 100 mL volumetric flask, mixing,bringing to volume with processed water, and sonicating for two minutes.

Test and resolution standard solutions were prepared using an analyticalbalance with a minimum weight of at least 5.00 mg in a humiditycontrolled area set to 30%±10% relative humidity. For test solution,5.00 to 6.00 mg of abaloparatide sample was added to a clean vial anddissolved in processed water to obtain a 1.0 mg/mL solution. Two samplesolutions (4-6.3.a and 4-6.3.b) were prepared.

For reference standard solution (RSS 1.0 mg/mL, H₂O), 5.00 to 6.00 mg ofabaloparatide (RDS-001) reference standard was added to a clean vial anddissolved in processed water to obtain a 1.0 mg/mL solution. Tworeference standard solutions (4-6.1.a and 4-6.1.b) were prepared.

For resolution standard solution (1.0 mg/mL 0.01N NaOH/neutralized by0.01N HCl), 5.00 to 6.00 mg of abaloparatide, API reference standard wasadded to a clean vial and dissolved in 0.01N sodium hydroxide to obtaina 2.0 mg/mL solution. The solution was heated at +40° C. for four hours,and the same volume of 0.01N hydrochloric acid was added to neutralizeand produce a 1.0 mg/mL degraded solution (4-6.2.1). For resolutionstandard solution dilution, reference standard solution (4-6.1.a) anddegraded solution (4-6.2.1) were injected successively as follows:

-   -   Integrate and determinate respectively area percent content for        RRT 1.07 degradation impurity.    -   Calculate the appropriate volume of each solution to be mixed to        obtain an area percent content for RRT 1.07 degradation impurity        between 2.0 and 2.5%.    -   Make the mixing and inject the Resolution standard solution to        check the content for RRT 1.07 degradation impurity. If        necessary, adjust the mixing.

Identification admixture (4-6.4) was prepared by mixing 250 μL ofreference solution (4-6.1.a) and 250 μL of test sample solution 4-6.3.a.

This method utilized a Waters Acquity BEH300 C4 1.7 150×2.1 mmanalytical HPLC column (Part No. 186004497). Detection was performed atUV 220 nm. The column temperature was +60° C.±2° C. and the autosamplertemperature was +10° C.±2° C. The injection volume was 5 μL, the flowrate was 300 μL/min, and the analysis stop time was 21.0 minutes.Elution conditions are set forth in Table 5.

TABLE 5 Elution conditions of Method 4 Time (min) % mobile phase A2 %mobile phase B2 0.0 52 48 1.5 52 48 18.5 39 61 19.0 1 99 21.0 1 99 21.552 48 25.0 52 48

The initial mobile phase composition may be adjusted within 0.0 and 18.5minutes, keeping the same gradient slope, in order to obtain anabaloparatide retention time between 12.5 and 13.5 minutes. The mobilephase composition at 19.0 and 21.0 minutes must be kept unchanged towash the column with 99% mobile phase B2.

The injection sequence was as follows:

-   -   Run 1: Baseline process water (wash)    -   Run 2: Resolution standard solution 4-6.2    -   Runs 3-7: Test solution 4-6.3.a    -   Run 8: Baseline process water    -   Run 9: Reference standard solution 4-6.1.a replicate 1    -   Run 10: Reference standard solution 4-6.1.a replicate 2    -   Run 11: Reference standard solution 4-6.1.b    -   Run 12: Test solution 4-6.3.a    -   Run 13: Test solution 4-6.3.b    -   Run 14: Reference standard solution 4-6.1.a    -   Run 15: Reference standard solution 4-6.1.b replicate 1    -   Run 16: Reference standard solution 4-6.1.b replicate 2    -   Run 17: Identification admixture 4-6.4

A maximum of five samples (10 injections) was allowed between twobracketing standards. Runs 2-15 are skipped when identification was notrequested. Runs 9-11 and 14-17 were skipped when content determinationis not requested.

Runs 2-8 would not be started unless the §9.1 System Suitability Test(SST) parameters were met.

Resolution standard solution (Run 2) was injected for the systemsuitability test, and the Empower CDS custom filed“Peak-to-valley-front-ratio” was used to report the Height/Valley ratiobetween abaloparatide and RRT 1.07 impurity peaks. This ratio should benot lower than 1.43.

Test solution injections(Runs 3-7) were further injected for the systemsuitability test, the following parameters must be calculated:

-   -   The relative standard deviation (RSD) of abaloparatide peak area        must be <2.0%.    -   The RSD of abaloparatide retention time must be <2.0%

Run 8 (blank injection) was carried out also for the system suitabilitytest, the area of any peak with a peak retention time corresponding tothat of abaloparatide must be <2.0% of the mean peak area of Runs 3-7injections.

The sample chromatograms were subtracted with any peak observed in theblank chromatogram (Run 8). The peak area reject was set to 0.05% of themean from abaloparatide peak area obtained for the duplicate injectionsfrom the sample.

Chromatogram obtained from Run 17 showed a single significant peak.

The individual related substance content and the sample purity weredetermined from Runs 12 and 13.

For each sample solution chromatogram, the sample purity in areanormalization was calculated according to the formula:

${{Sample}\mspace{14mu} {overall}\mspace{14mu} {purity}\mspace{14mu} \left( {{{area}\mspace{14mu} \%},{1\mspace{14mu} {decimal}}} \right)} = {\frac{{Peak}\mspace{14mu} {area}\mspace{14mu} {RDS}\text{-}001}{{Peak}\mspace{14mu} {area}\mspace{14mu} {of}\mspace{14mu} {all}\mspace{14mu} {peaks}\mspace{14mu} {in}\mspace{14mu} {chromatogram}} \times 100}$

“Any unspecified impurity” term corresponds to the highest individualimpurity, excluding the known impurities such as the truncated peptidesand the beta-asp 10 isomer.

The level of total impurities was calculated according to the formula:

Total impurities(area %, 1 decimal)=100−overall purity

The beta-Asp10 isomer (RDS-001-A01) was eluted at approximately RRT0.97. For each sample solution chromatogram, the beta-Asp10 isomer levelwas calculated in area normalization according to the formula:

${{Beta}\text{-}{asp}\; 10\mspace{14mu} {isomer}\mspace{11mu} \left( {{\% \mspace{14mu} {area}},{1\mspace{14mu} {decimal}}} \right)} = {\frac{{Peak}\mspace{14mu} {area}\mspace{14mu} {Beta}\text{-}{asp}\; 10\mspace{14mu} {isomer}}{{peak}\mspace{14mu} {area}\mspace{14mu} {of}\mspace{14mu} {all}\mspace{14mu} {peaks}\mspace{14mu} {in}\mspace{14mu} {chromatogram}} \times 100}$

The truncated peptides were eluted at approximately at RRT 0.92(RDS-001-106; ATP (3-34) and RRT 0.93 (RDS-001-105; ATP(4-34)). For eachsample solution chromatogram, the RDS-001-105 and RDS-001-106 levelswere calculated in area normalization according to the formula:

${{Truncated}\mspace{14mu} {peptides}\mspace{14mu} \left( {{\% \mspace{14mu} {area}},{1\mspace{14mu} {decimal}}} \right)} = {\frac{{Peak}\mspace{14mu} {area}\mspace{14mu} {RDS}\text{-}001\text{-}105\mspace{14mu} {and}\mspace{14mu} {RDS}\text{-}001\text{-}106}{{peak}\mspace{14mu} {area}\mspace{14mu} {of}\mspace{14mu} {all}\mspace{14mu} {peaks}\mspace{14mu} {in}\mspace{14mu} {chromatogram}} \times 100}$

The abaloparatide content in each test solution chromatogram ascalculated according to the formula below and as final result the meancontent from the two sample preparations

${{RDS} - {001\mspace{14mu} {content}\mspace{14mu} \left( {{w\text{/}w\mspace{14mu} \% \mspace{14mu} {area}},{1\mspace{14mu} {decimal}}} \right)}} = {\frac{{As} \times {Qr} \times {Cref} \times {Pref}}{{Ar} \times {Qs} \times 100 \times 100} \times 100}$

where:

-   As: Abaloparatide peak area obtained in the test solutions-   Ar: Mean of abaloparatide peak areas in the six bracketing    injections of reference standard-   Qr: Injected quantity of reference standard (μg)-   Qs: Injected quantity of sample (μg)-   Cref: peptide content of the reference standard calculated as per    following formula:

Cref=100−H₂0(% w/w)−AcOH(%w/w)−residual TFA(%w/w)

(Water content determined the same day as the reference standardsolution is prepared).

-   Pref: Mean of abaloparatide peak purity in the six bracketing    injections of reference standard-   100: factor for conversion of content expressed as mg/mL.-   Chromatograms from Method 4 are shown in FIGS. 9A-C.

Example 2 Comparison of Methods 1 and Method 3 on Formulated Drug

The HPLC method in TFA solvent system was validated and implemented asdescribed in Method 1. In addition, Method 3 describes aphosphate-buffered mobile phase. Method 1 and Method 3 were compared forthe same abaloparatide formulated drug sample. These results are shownin FIGS. 10A-B. A front running impurity peak not previously seen whenusing Method 1 (or 2) was separated out using Method 3. In addition, thetwo truncated peptides (ATP(3-34) and ATP(4-34)) were resolved using theUPLC method as described below.

TABLE 6 Formulated drug product batch analysis by Method 1. Purity areasand relative retention times (“RRT”; abaloparatide = 1) BEJH09 a BEJH09b BEJJ12 a BEJJ12 b BEJH09 c % % % % % RRT area RRT area RRT area RRTarea RRT area 0.45 0.05 0.45 0.06 0.45 0.05 0.45 0.05 0.45 0.06 0.970.18 0.97 0.17 0.97 0.19 0.97 0.18 0.97 0.19 1.00 99.6 1.00 99.6 1.0099.5 1.00 99.5 1.00 99.5 1.14 0.13 1.13 0.05 1.14 0.07 1.13 0.07 1.130.06 — — — — — — — — 1.25 0.05 — — — — — — — — 1.40 0.05

TABLE 7 Formulated drug product batch analysis by Method 3. Purity areasand relative retention times (“RRT”; abaloparatide = 1) BEJH09 a BEJH09b BEJJ12 a BEJJ12 b BEJH09 c % % % % % RRT area RRT area RRT area RRTarea RRT area 0.17 0.12 0.17 0.06 0.17 0.08 0.17 0.08 0.17 0.09 0.650.07 0.63 0.07 0.64 0.07 0.64 0.06 0.65 0.07 0.73 0.09 0.72 0.08 0.730.08 0.73 0.08 0.73 0.09 — — 0.83 0.06 — — — — 0.84 0.05 — — 0.89 0.05 —— — — 0.92 0.13 0.91 0.15 0.91 0.14 0.91 0.13 0.92 0.14 0.94 0.16 0.940.18 0.94 0.17 0.94 0.17 0.94 0.15 0.97 3.08 0.97 3.16 0.97 3.06 0.973.05 0.97 3.15 1.00 95.1  1.00 94.9 1.00 95.2  1.00 95.2  1.00 95.0 1.07 0.78 1.08 0.81 1.07 0.66 1.07 0.71 1.07 0.87 1.11 0.17 1.12 0.091.10 0.15 1.10 0.16 1.15 0.13 — — 1.15 0.15 1.15 0.08 1.15 0.09 — — — —1.17 0.06 — — — — — — 1.29 0.15 1.30 0.11 1.29 0.17 1.29 0.15 1.29 0.14

The front running peak at RRT 0.97 under using Method 3 was subsequentlyidentified as (beta-Asp10) abaloparatide, whose characterization will bedescribed in detail later. Given the surprising and beneficialseparation conferred by the use of a phosphate buffer in the mobilephase, it was decided to take a detailed look at the relativeperformance of HPLC vs UPLC using first, non-buffered mobile phase(Example 3) and buffered.

Example 3 Comparison of Methods 1 and 2 in Purifying AbaloparatideSamples

Method 2 (UPLC, no buffer) was compared to Method 1 (HPLC, no buffer) onan API sample manufactured in 2012 (“8AK1”). The results are juxtaposedin FIG. 11A and FIG. 11B.

Several batches were analysed using Method 1 and Method 2 and theimpurity profiles have been compared (as shown for 1 batch in Table 8below). The impact on the impurity profiles was acceptable regarding thecomparison between HPLC and UPLC results for Methods 1 and 2, theresults from UPLC version provided at least the same level of qualityand furthermore provide better resolution of impurities and API mainpeak.

TABLE 8 Abaloparatide API batches Batch Nature Year of production 4AI1API 2010 4AI2 API 2010 4AI1R RS 2010 3AJ1 API 2011 8AK1 API 2012 8AK1RRS 2012 3AL1 API 2013 7AL1 API 2013 10AL1 API 2013 10AL2 API 2013

TABLE 9 Impurity profiles according to Method 1 % area Method 1-TFA -HPLC RRT 4AI1 4AI2 4AI1R 3AJ1 8AK1R 8AK1 3AL1 7AL1 10AL1 10AL2 0.82 — —— — — 0.07 — — — 1.00 99.74 99.51 99.52  99.86 99.73  99.77 99.79 99.9499.70  99.89 1.07-1.08 — 0.15 0.18  0.10 0.08  0.09 0.08 — 0.20 —1.11-1.13  0.10 0.13 0.15 — 0.06 — — — —  0.11 1.15 — — — — — — — 0.10 —1.31 — 0.09 0.08 — — — — — — —

TABLE 10 Impurity profiles according to Method 2 % area Method 2-TFA -UPLC RRT 4AI1 4AI2 4AI1R 3AJ1 8AK1R 8AK1 3AL1 7AL1 10AL1 10AL2 0.94 — —— 0.05 — — 0.10 — — — 0.99 — — — — — — — — 0.06 0.05 1.00 99.07  99.12 99.23  99.50  99.72  99.63  99.30  99.51  99.15  99.50  1.02-1.03 0.370.42 0.34 0.29 0.22 0.21 0.30 0.29 0.52 0.27 1.03 0.11 0.13 0.12 0.100.06 0.11 0.09 0.08 0.12 1.04 0.16 0.17 0.13 0.06 0.06 0.10 0.19 0.110.13 0.05 1.05 — — 0.06 — — — — — — — 1.06 — — 0.08 — — — — — — — 1.070.10 0.08 0.05 — — — — — — — 1.09-1.10 0.07 0.07 — — — — — — 0.06 — 1.120.06 — — — — — — — — — 1.16 0.06 — — — — — — — — —

Example 4 Development/Optimization of Method 4 in PurifyingAbaloparatide Samples Evaluation of Gradient on C18 Column

Different gradient systems were tested to assess the best gradientcondition to discriminate the truncated peptides (RDS-001-I05 andRDS-001-I06).

Analytical Conditions—UPLC

-   Columns: UPLC Acquity BEH C18 1,7μ 150*2.1 mm-   Mobile phase A: 64 mM (NH₄)₂HPO₄ in H₂O pH 7.8-   Mobile phase B: (56 mM (NH₄)₂HPO₄ pH 7.8 in H₂O/ACN 50/50-   Flow rate: 400 μl/min-   Detection: 220 nm-   Gradient: 37% B 1′-37-61% B in 10′-   Column temperature: 60° C.-   Sample temperature: 10° C.-   Injected volume: 5 μl-   Sample concentration: 5 μg/5 μl H₂O

Truncated Peptides

The RDS-001-I06 impurity peak were eluted before the abaloparatide(RDS-001) peak, but the RDS001-I05 impurity peak has the same retentiontime then the abaloparatide peak (see FIG. 12A). With a faster gradient,the impurities remained under the peak. With an isocratic elution at 50%mobile phase B, the 2 impurities peaks were eluted before theabaloparatide (RDS-001) peak but the RDS-001-I05 peak shape was wide(see FIG. 12B).

To avoid crystallizing problems in the B phase, 40% of acetonitrile wasprepared instead of the 50%. The isocratic elution was changed to 60% B.

Evaluation of Column Temperature

Different column temperatures were tested to assess the best gradientcondition to discriminate the truncated peptides (RDS-001-I05 andRDS-001-I06).

Truncated Peptides

Impact of the column temperature was tested from 40° C. to 90° C. The 2peaks began to be separated from main peak at +55° C. and thisseparation improved until +90° C. Results for each temperature are shownin FIG. 12C-12J, and an overlay of the results for +55° C. and +90° C.is shown in FIG. 12K.

Further Exploration of Conditions Using C18 Column Analytical Conditions

-   Columns: UPLC Acquity BEH C18 1,7μ 150*2.1 mm-   Mobile phase A: 64 mM (NH₄)₂HPO₄/H₂O pH 7.8-   Mobile phase B: (58% 160 mM (NH₄)₂HPO₄/H₂O pH 7.8, 42% H₂O)/ACN    60/40-   Flow rate: 0.5 ml/min-   Detection: 220 nm-   Gradient: 60% B -60-70% B in 15′-   Column temperature: 90° C.-   Sample temperature: 10° C.-   Injected volume:-   Sample concentration: 5 μg/5 μl H₂O

Truncated Peptides

C18 column results are shown in FIG. 12L.

Truncated peptides were well separated from the main peak but columns C4and C8 were evaluated in the hope that they might improve thediscrimination in front peak and decrease the tailing. It was discoveredthat a C4 column substantially improved both front end discriminationand decreased tailing, particularly after further optimization.

Evaluation of C4 and C8 Columns Analytical Conditions

-   Columns: UPLC Acquity BEH C8 1,7μ 150*2.1 mm-   Mobile phase A: 64 mM (NH₄)₂HPO₄/H₂O pH 7.8-   Mobile phase B: (58% 160 mM (NH₄)₂HPO₄/H₂O pH 7.8, 42% H₂O)/ACN    60/40-   Flow rate: 0.5 ml/min-   Detection: 220 nm-   Gradient: 60%B - 60-70% B in 15′-   Column temperature: 90° C.-   Sample temperature: 10° C.-   Injected olume: 5 μl-   Sample concentration: 5 μg/5 μl H₂O

Truncated Peptides

C8 column results are shown in FIG. 12M. The peak shape was not improvedwith C8 column.

Phosphate Solvent System Using UPLC/C4 Column Analytical Conditions

-   Columns: UPLC Acquity BEH C4 1,7μ 150*2.1 mm-   Mobile phase A: 64 mM (NH₄)₂HPO₄/H₂O pH 7.8-   Mobile phase B: (58% 160 mM (NH₄)₂HPO₄/H₂O pH 7.8, 42% H₂O)/ACN    60/40-   Flow rate: 0.5 ml/min-   Detection: 220 nm-   Gradient: 55% B - 55-65% B in 15′-   Column temperature: 90° C.-   Sample temperature: 10° C.-   Injected volume: 5 μl-   Sample concentration: 5 μg/5 μl H₂O

TABLE 11 Peaks of impurities RDS-001-I05 and RDS-001-I06 under Method 4TR RRT vs RDS-001 RDS-001-I05 11.182 0.882 RDS-001-I06 10.700 0.851

FIG. 12N presents the overlay of 3 chromatograms:

-   -   Abaloparatide, API spiked with RDS-001-I05 (Blue)    -   Abaloparatide, API spiked with RDS-001-I06 (Red)    -   Abaloparatide, API unspiked (Black)

The impurities were better discriminated from the main peak using a C4column compared to C18-UPLC method, and resolution of impurities in thetailing was better.

Sample Analyses (API and IPC)

FIGS. 12O-12S show resolution of ATP(3-34) and ATP(4-34) across a numberof abaloparatide samples, namely 8AG1 (FIG. 12O), 6AG1R (FIG. 12P),RDHAG112 Fp1 (FIG. 12Q), RDHAG112 FpAv (FIG. 12R), and RDHAG112 FpArr(FIG. 12S).

Evaluation of Flow Rate and Gradient to Obtain Similar SeparationCharacteristics as Obtained by Using +90° C. as Column Temperature

While a column temperature of (+90° C.) was very effective in improvingthe separation of impurities as explained above, such a high temperaturemay add or accelerate to the degradant profile of the drug. Twodifferent flow rates (reduced) were evaluated at column temperature of(+60° C.) with an adapted gradient using a C4 column.

Analytical Conditions

-   Columns: UPLC Acquity BEH C4 1,7μ 150*2.1 mm-   Mobile phase A: 64 mM (NH₄)₂HPO₄/H₂O pH 7.8-   Mobile phase B: (58% 160mM (NH₄)₂HPO₄/ H₂O pH 7.8, 42% H₂O)/ACN    60/40-   Flow rate: 0.4 ml/min and 0.3 ml/min-   Detection: 220 nm-   Gradient: 45% B 1.5′-45-60% B in 15′-   Column temperature: 60° C.-   Sample temperature: 10° C.-   Injected volume: 5 μl-   Sample concentration: H₂O

FIG. 12T and FIG. 12U show the effect of flow rate on peak shape andresolution for 8AG1 on the phosphate/C4 column.

The column temperature at +60° C. was kept for future analyses. BothHPLC (Method 3) and UPLC (Method 4) used similar phosphate buffer.Several batches were analysed comparing HPLC and UPLC methods and theimpurity profiles have been compared.

The impurities with a higher RRT than the main peak were betterseparated from the main peak in UPLC phosphate buffer method (Method 4)than HPLC phosphate buffer method (Method 3). The tailing of the mainpeak obtained in Method 3 may also contribute to the lower resolution ofimpurities from the main peak observed.

The UPLC analytical method showed improved resolution of impurities fromAPI main peak compared to the HPLC method using the same solvent system.

TABLE 12 Impurity profiles under Method 3 conditions Method 3 - HPLC RRT4AI1 4AI2 4AI1R 3AJ1 8AK1R 8AK1 3AL1 7AL1 10AL1 10AL2 0.73-0.74 0.080.09 0.08 — — — 0.10 0.07 0.10 — 0.88-0.89 0.05 — 0.05 — — — — — —0.91-0.92 0.13 0.11 0.11 — — 0.05 — 0.05 — — 0.94 0.18 0.17 0.17 0.10 —0.06 0.08 0.19 0.15 0.11 0.97-0.98 0.29 0.28 0.28 0.25 0.85 0.87 0.310.27 0.42 0.32 1.00 98.42 98.89 98.17  98.76  98.46  98.39  98.21 99.20  98.94  99.25  1.06-1.07 0.56 0.60 0.62 0.51 0.34 0.34 0.66 — — —1.09-1.10 0.14 0.09 0.28 0.12 — — — — — — 1.13-1.14 0.13 0.25 0.19 0.230.25 0.37 0.14 0.06 0.15 1.15-1.16 — 0.07 — 0.11 — — 0.14 — — — 1.2  —0.07 — — — — — — — —

TABLE 13 Impurity profiles according to Method 4 Method 4 - UPLC RRT4AI1 4AI2 4AI1R 3AJ1 8AK1R 8AK1 3AL1 7AL1 10AL1 10AL2 0.74 0.04 0.050.05 0.05 — — 0.08 0.05 0.05 — 0.79 0.06 0.06 0.07 — — — — — 0.08 — 0.890.10 0.10 0.12 — — — — 0.05 0.10 — 0.90 — — — — — — — 0.07 — 0.93 0.110.13 0.11 — — — 0.05 0.10 — 0.94 0.08 0.05 0.14 0.09 0.14 0.10 0.08 0.100.13 0.09 0.95 0.06 0.08 — — — 0.05 — — — — 0.97 0.18 0.19 0.20 0.150.10 0.11 0.06 0.11 0.10 0.16 1.00 98.88  98.83  98.57  99.30  99.32 99.36  99.37  99.31  98.79  99.37  1.13-1.14 0.07 0.08 0.11 — — — 0.080.11 0.11 0.06 1.14 — — — — — — 0.08 — — — 1.16-1.17 0.17 0.24 0.15 0.230.39 0.39 0.22 0.17 0.19 0.14 1.18 0.09 — 0.15 — — — — — — — 1.21-1.22 —0.07 0.11 0.10 — — — 0.05 0.09 0.09 1.23-1.24 — — 0.04 — — — — — 0.06 —1.25-1.26 0.13 0.12 0.14 0.08 0.05 — — 0.05 0.11 0.10

Example 5 Stability Indicating Methods TFA Solvent System Methods(Methods 1 and 2) HPLC v UPLC

Chromatograms for acid stress (HCl 1N), base stress (NaOH 0.01N), andheat stress (+80° C.) for Method 1 are set forth in FIGS. 13A, C, and E,respectively. Chromatograms for acid stress (HCl 1N), base stress (NaOH0.01N), and heat stress (+80° C.) for Method 2 are set forth in FIGS.13B, D, and F, respectively.

Ammonium Phosphate Solvent Methods (Method 3 and Method 4)

Chromatograms for acid stress (HCl 1N), base stress (NaOH 0.01N), andheat stress (+80° C.) for Method 3 are set forth in FIG. 13G, I, and K,respectively. Chromatograms for acid stress (HCl 1N), base stress (NaOH0.01N), and heat stress (+80° C.) for Method 4 are set forth in FIGS.13H, J, and L, respectively.

HPLC and UPLC using the phosphate-buffer (methods 3 and 4) providedsimilar impurity profiles. However, UPLC method (Method 4) providebetter impurities discrimination and reduced tailing effects. As can beseen, methods 3 and 4 were considerably better at resolvingstress-derived impurities in the chromatograms.

Examples of the methods disclosed herein are summarized below.

TABLE 14 TFA Solvent System (Method 1 and Method 2) Method 1 Method 2Column Zorbax 300SB C8 5 μm Column Waters Acquity CSH C18 250 × 4.6 mm(or equivalent) 1.7 μm, 100 × 2.1 mm Column Temperature +50° C. ColumnTemperature +40° C. Autosampler temperature +10° C. Autosamplertemperature +10° C. Flow rate 0.9 mL/min Flow rate 300 μL/min Detectionwavelength UV: 220 nm Detection wavelength UV: 220 nm Injection volume20 μL Injection volume 2 μL Elution conditions Gradient: Elutionconditions Gradient: Time % mobile % mobile Time % mobile % mobile(min.) phase A phase B (min.) phase A2 phase B2 0.0 71 29 0.0 68 32 25.065 35 0.5 68 32 35.0 65 35 14.5 40 60 36.0 71 29 15.0 20 80 45.0 71 2915.5 20 80 15.6 68 32 18.0 68 32 Analysis stop time 35 minutes Analysisstop timer 14.5 minutes

TABLE 15 Ammonium Phosphate Solvent System (Method 3/Method 4) Method 3Method 4 Column X-Bridge C18, 5 μm, Column Waters BEH300 C4 150 × 4.6 mm1.7 μm, 150 × 2.1 mm Column Temperature +60° C. Column Temperature +60°C. Autosampler temperature +15° C. Autosampler temperature +10° C. Flowrate 0.8 mL/min Flow rate 300 μL/min Detection wavelength UV: 214 nmDetection wavelength UV: 220 nm Injection volume 20 μL Injection volume5 μL Elution conditions Gradient: Elution conditions Gradient: % mobile% mobile Time % mobile % mobile eta phase A phase B (min.) phaseA2phaseB2 0.0 77 23 0.0 52 48 12.0 53 47 1.5 52 48 46.0 53 47 18.5 39 6156.0 43 57 19.0 1 99 58.0 0 100 21.0 1 99 63.0 0 100 21.5 52 48 65.0 7723 25.0 52 48 75.0 77 23 Analysis stop time 60 minutes Analysis stoptimer 21.0 minutes

Example 6 Kinetics of beta-Asp10 Formation And Appropriate StorageDetermination

When older clinical lots of abaloparatide-SC (aqueous formulated drugproduct) that had been kept in refrigerated storage for more than 36months (C12689, D26565, and D28382) were analyzed using the new HPLCmethod (Example 3), a new degradant was separated that had not beendetected by previous chromatographic methods. Subsequent analysesdemonstrated that this degradant was also present in varying amounts inAPI (though less than formulated and stored samples). The new degradantwas isolated, purified, and analyzed, and structural analysis indicatedthat it was beta-Asp10. Beta-Asp10 contains a rearrangement of the Aspresidue at position 10 arising from a temperature-dependent hydrolysisreaction. This reaction is illustrated in FIGS. 1A-C.

Analysis of the older lots (i.e., older than 36 months) indicated thatmore than 3% of the abaloparatide in the formulation could be convertedto abaloparatide (beta-Asp10). Analysis of newer clinical lots stored atone month for room temperature indicated that the percentage of(beta-Asp10) in the formulation could be more than 1%. Table 16summarizes these analyses, and shows the differences in impuritydetection between the original HPLC method (no buffer)(“original testmethod”) and the improved method (buffered) (“current test method”).

TABLE 16 Comparative analysis of abaloparatide-SC drug product clinicaland stability batches Clinical & Stability Clinical & Stability Clinical& Stability Batch C12689 Batch D26565 Batch D28382 Original test Currenttest Original test Current test Original test Current test methodMethods method Methods method Methods 5° C. 5° C. 5° C. 5° C. 5° C. 5°C. Method Specifications 36 months ~54 months 36 months ~41 months 36months ~38 months Abaloparatide 1.8-2.2 2.00 — 1.97 — 1.94 — Assay¹(mg/mL) Total impurities¹ ≤3.0 0.3 — 0.2 — 0.2 — (%) Abaloparatide1.8-2.2 — 1.91 1.95 — 1.90 Assay² (mg/mL) Total impurities² ≤3.0 — 5.34.0 — 3.8 (%) beta-Asp10 isomer ND 4.0 ND 3.1 ND 3.0 content (%)¹Testing performed with original methodology, HPLC method - TG1 ²Testingperformed with revised methodology, UPLC method FG2 ND = not detected

As can be seen, the new methods of analysis allowed for significantresolution of abaloparatide samples when compared to older methods usingHPLC and/or non-ionic buffering solvents.

of significance was the identification and qualification of a heretoforeunidentified isomer of abaloparatide, (beta-Asp10) abaloparatide. Bycomparing a number of samples stored under different conditions, therate of formation of (beta-Asp10) abaloparatide could be accuratelyquantified and plotted on a time course at a given temperature.

The predictability of (beta-Asp10) abaloparatide formation in theformulated drug product was established and the isomerization ofabaloparatide to the isomer occurred according to strictly zero orderkinetics.

(beta-Asp10) abaloparatide analog levels (mean) in registration batchesat different storage conditions are given in the Table 17 immediatelybelow.

TABLE 17 (beta-Asp10) abaloparatide levels in formulated samples by timeTime Point Temp 0 M 1 M 3 M 6 M 9 M 12 M 18 M 24 M 5° C. Long 0.3 — 0.50.76 0.96 1.03 1.66 1.93 term storage condition (%) 25° C. 0.3 1.26 3.266.3 9.43 11.96 16.73 20.73 (Accelerated condition) (%) 40° C. (Stress0.3 7.10 18.76 32.9 — — — — condition) (%)

Formation of (beta-Asp10) abaloparatide analog was plotted against timein months (see FIG. 7), which resulted in an excellent straight line fitfor data at each temperature condition, suggesting that rate offormation of (beta-Asp10) abaloparatide, and therefore rate ofisomerization for abaloparatide, follows zero order kinetics. The slopeof the straight line for each temperature was the observed rate constant(K_(obs)) for formation of (beta-Asp10) abaloparatide. Rate constants ateach temperature are tabulated in the top row of Table 18.

TABLE 18 Observed rate constant at various temperature Temp 40° C. 25°C. 5° C. k_(obs) (%/month) 5.38 0.993 0.0690 K_(calc) (%/month) 5.190.938 0.0674 Difference (%) 3.5 −5.6 2.3

Arrhenius Plot and Calculation of Activation Energy for AbaloparatideDegradation.

An Arrhenius plot was constructed (FIG. 8) by plotting the naturallogarithm of the rate constants (k) for three storage temperatures,against the reciprocals of those temperatures in Kelvin. The plotindicates that the rate of formation of (beta-Asp10) abaloparatide ishighly predictable at temperatures between 5° C. and 40° C., with a R2value of 0.9997 for best linear regression fit of the data. Theactivation energy, Ea, derived with high accuracy from the slope of alinear regression best fit of the Arrhenius plot is Ea=91,670 J/mol.This activation energy can be used to calculate the rate constant forabaloparatide isomerization and (beta-Asp10) abaloparatide formation atany temperature. A comparison of the calculated rate constants to thecorresponding, measured real time rate constants derived from a linearfit of the data in Table 18, demonstrates predictability with highprecision. For example, the observed rate constant at 5° C.,K_(obs)=0.0655%/month agrees well with the predicted value,K_(calc)=0.0644%/month, with only a 0.0011% absolute difference and a1.7% relative difference. [000169] The amount of b-Asp10 in the API mustbe determined with rigor and set accordingly to achieve the desiredstability profile after pre-specified storage conditions. Previously,this could not be done as the methods used were insufficient for itsidentification and quantification. Therefore, not only has a newdegradant been discovered but the methods described herein have allowedthe formation rate equation to be determined and thus allow for settingits specification in the API when coupled with a desired storagestability profile. Based on calculations from the extrapolated datademonstrating a very linear time-product course across differenttemperatures including refrigerated conditions (2-8° C.) and roomtemperature (e.g., 20-25° C.), it was determined that a predeterminedset point of ≤5% of (b-Asp10) could be secured using abaloparatide APIstarting with <0.5% (b-Asp10) and stored for up to 23 months atrefrigerated conditions followed by up to one month at room temperature.It was also shown that the desired ≤5% (beta-Asp10) abaloparatide levelcould be secured using abaloparatide API starting with ≤0.5%; as storagefor 35 months at refrigerated conditions followed by up to one monthroom temperature contained desired ≤5% (beta-Asp10) abaloparatide. Amethod of stability confirmation is also provided comprising the storageof abaloparatide for 23 months under refrigerated conditions followed byone month at room temperature, or 35 months under refrigeratedconditions followed by one month at room temperature, wherein evaluatingfor (beta-Asp10) in the starting API predicts the ultimate acceptabilityof an aqueous formulation containing abaloparatide. In order for therequired purity to be met for abaloparatide drug product, the API mustbe analyzed as enabled by the novel methods of LC analysis describedherein and needs to be ≤0.5% (b-Asp10). Similarly, the API, onceformulated into cartridges is tested for purity including evaluation for(b-Asp10) right after the cartridge is formulated. This is also animportant evaluation point for (b-Asp10) because the formulation itselfrequires time to complete mixing and filling prior to refrigeration.Therefore, the evaluation of formulated abaloparatide at this time point(designated t=0 here) is undertaken and it has been determined that the(b-Asp10) amount needs to be <1.0% for the desired purity level of thefinal drug.

As indicated above, the hydrophobicity of the column can be optimizedeffectively to the particular result required. Accordingly, in someembodiments of this disclosure a method of analyzing an abaloparatidesample is disclosed wherein a Cx-Silicon based reversed phase column isemployed. In certain embodiments, the carbon component of the column is16 carbons, 8 carbons or 4 carbons in linear length. In certainembodiments, the linear chain is further branched with varying alkylgroups (e.g., isopropyl). In certain embodiments, the column temperaturewas elevated above rt. For example, a column temperature of between40-90° C. can be effectively employed across a range of Cx-Si reversephase columns. In certain embodiments, a range of temperatures between40-80° C., 40-70° C. or 40-60° C. can also be effectively used. Inparticular, column temperatures of about 40° C., 45° C., 50° C., 55° C.,or 60° C. are all effective embodiments.

Biological characterization of (beta-Asp10) abaloparatide was evaluatedin a qualified cell base potency assay for functional PTH activity usingthe production of cAMP as a measure of bioactivity. The results obtainedin this study showed that the EC₅₀ was 3.297 ng/mL for (beta-Asp10)abaloparatide and the EC₅₀ of abaloparatide was 0.325 ng/mL forabaloparatide.

As stated above, the foregoing is merely intended to illustrate variousembodiments of the present invention. The specific modificationsdiscussed above are not to be construed as limitations on the scope ofthe invention. It will be apparent to one skilled in the art thatvarious equivalents, changes, and modifications may be made withoutdeparting from the scope of the invention, and it is understood thatsuch equivalent embodiments are to be included herein. All referencescited herein are incorporated by reference as if fully set forth herein.

1. A method of analyzing a sample containing abaloparatide comprisingusing an HPLC and/or UPLC using a binary solvent system with a mobilephase comprising an aqueous buffer. 2-4. (canceled)
 5. The method ofclaim 1 wherein said aqueous buffer has a pH range of between 6-10, orbetween 7-9, or between 7.5-8.5, or between 7.6-8.0 in the aqueous phaseprior to mixing with any additional mobile phase solvent(s). 6-8.(canceled)
 9. The method of claim 5 wherein said aqueous buffer has a pHrange of about 7.8 in the aqueous phase prior to mixing with anyadditional mobile phase solvent(s).
 10. (canceled)
 11. The method ofclaim 1 wherein said aqueous buffer comprises a phosphate or sulfonateion, a phosphate, NH₄H₂PO₄, or an ammonium phosphate buffer. 12-18.(canceled)
 19. An aqueous abaloparatide formulation comprisingabaloparatide and <5% (beta-Asp10) abaloparatide of the total peptidecontent. The formulation according to claim 19, wherein the formulationhas a pH of 4.5 and 5.5.
 21. The formulation according to claim 19,wherein the formulation has a pH of about 5.1.
 22. The formulationaccording to claim 19 containing an acetate buffer.
 23. The formulationaccording to claim 19 having an abaloparatide concentration between 1.8and 2.2 mg/mL. 24-38. (canceled)
 39. An aqueous abaloparatideformulation comprising ≤1.0% w/w (beta-Asp10), ≤0.5% ATP(3-34), ≤0.5%ATP(4-34), ≤0.5%(cyclo-Asp10), and ≤0.5% (cycloAspl7) of the totalpeptide content, and an aqueous buffer having a pH of from 4.5-5.5,wherein said formulation has an abaloparatide concentration of between1.8 mg/mL and 2.2 mg/mL.